I have the dreaded engine code:O
 

I finally got all of the stuff fixed on my 02 Boxter S yesterday. The mods I have are a set of headers with the relocated O2 sensors, a Borla muffler and the canned oil filter adapter with the M1-107 filter. The Mufflers have been there since I got the car, the headers have been on for several weeks and I just did the filter mod yesterday and changed to Mobil1 15w50 synthetic oil. So I get about 8 miles from the house and the engine light comes on. I can't imagine the headers took this long to cause a problem nor can I imagine the filter and oil change would do it but what do I know. Anyone else experience something like this? I'm going to Autozone this afternoon to get the codes read but any advise would be appreciated!!

Thanks,

Jeff

Posting the codes would be a big help as a CEL can be caused by a number of things.

I don't know what kind of exhaust setup you have but when re-installing the rear O2 sensor, distance from the cat convertor is important (also when replacing a non-OEM cat).

Regards,
paul...

http://forums.pelicanparts.com/uploa...1334762577.gif

Like a strong wind in the right direction. LOL Ronster is right. Ya never know.

Randy

I was going to say you're farting into the wind, Randy, but I decided to try and have a little class.:D

LMAO!!! Thanks, Randy

And the winners are......

P1276 and P1053

Doing a search on them now!!

The headers I got move the first oxygen sensor to one of the exhaust pipes at a point between the head and just before the three pipes combine. The second sensor is in the header just before the header connects to the secondary cat pipe. This shows the computer two different readings and fools it into thinking the cat is still there. As I said though, I've driven quite a bit with the headers installed before the light came on. No idea how the system works though.

Jeff

Jeff, Here is what I found posted by Loren on Renntech.

P1276 Signal Delay Time for Oxygen Sensor Ageing, Bank 2 – Above/Below Limit
P0153 Signal Period for Oxygen Sensor Ageing, Bank 2 – Above/Below Limit

Potential causes:
– Oxygen sensor ahead of TWC
– Wiring (oxygen sensors exchanged)
– Leak ahead of TWC or in the area of the oxygen sensor after TWC

If the wiring/connectors are good - it does look like a sensor.

Randy

And here's the explanation;

P1276 Aging of Oxygen Sensor Ahead of Catalytic Converter (Cylinders 4 - 6) - Below Lower Limit

Now I would take it that I haved to replace that oxygen sensor......or is this one of those codes that could actually be caused by something else?

Jeff

As I have seen suggested by other with O2 problems. Switch the sensors and clear the codes. But there is always a chance that the other one my be bad as well. Just a thought. Not likely. But a chance?
Randy

Do you know off hand what side bank 2 or cylinders 4 to 6 are?

Jeff

If memory serves me correctly? 4-6 is the passenger side. But you can do a search for Boxster cylinder banks on google and get it. It think in Europe they are reversed. But been awhile since I searched.
Randy

I don't have the Durametric scanner. Can the unit they use at Autozone clear the code? Does disconnecting the battery clear the code?

Jeff

Just checked and It looks like I am wrong. It's the other way around.

Randy

Oooh! Emission control codes, you're in deep Bandini now. Time to employ someone who knows and understands the Porsche Diagnostic Tree otherwise you can chase your tail for a very long time.

If only this were my only car with a check engine light problem!!! Fortunately we don't have emission checks here in sunny SC. I just want to be sure it doesn't cause any other more serious issues by changing the tune on the engine. Other than that it's nothing a small piece of electrical tape won't fix!:D

Jeff

Hey all,

I swapped the pre oxygen sensors as suggested. It took about 150 miles but the check engine light came on again. It came on when I started the car this time after letting it set for four hours after a 100 mile trip rather than when driving on the highway. This time the code came back as P0430 which is Catalytic Converter Conversion Too Low (Cylinders 4 - 6). That's on the same bank as it was before even though I swapped the pre oxygen sensors from side to side. If you'll remember I removed the primary cats and replaced them with headers that relocated the oxygen sensors since one of my cats was loose inside. Also, the car still doesn't run smoothly at highway speed. The guy at the Autozone where I took it suggested that possibly a change in back pressure with the new headers may cause that issue.....any thoughts? The possible causes that came up on the Autozone code sheet are an exhaust air leak, AF sensor error or a fuel system fault. He also said I may need to flash the computer to account for the change in the exhaust system.

My other issue is I just plain can't stand the exhaust sound on this car. It's too loud until you get the car over 3k rpm so I may need to get that figured out first. Trips in this car are down right unpleasant the way it is!! It currently has a set of Borla mufflers installed. I'm looking for other suggestions to quiet the car down from there.

I'd appreciate any thoughts or suggestions!

Jeff

Hey all,

I swapped the pre oxygen sensors as suggested. It took about 150 miles but the check engine light came on again. It came on when I started the car this time after letting it set for four hours after a 100 mile trip rather than when driving on the highway. This time the code came back as P0430 which is Catalytic Converter Conversion Too Low (Cylinders 4 - 6). That's on the same bank as it was before even though I swapped the pre oxygen sensors from side to side. If you'll remember I removed the primary cats and replaced them with headers that relocated the oxygen sensors since one of my cats was loose inside. Also, the car still doesn't run smoothly at highway speed. The guy at the Autozone where I took it suggested that possibly a change in back pressure with the new headers may cause that issue.....any thoughts? The possible causes that came up on the Autozone code sheet are an exhaust air leak, AF sensor error or a fuel system fault. He also said I may need to flash the computer to account for the change in the exhaust system.

My other issue is I just plain can't stand the exhaust sound on this car. It's too loud until you get the car over 3k rpm so I may need to get that figured out first. Trips in this car are down right unpleasant the way it is!! It currently has a set of Borla mufflers installed. I'm looking for other suggestions to quiet the car down from there.

I'd appreciate any thoughts or suggestions!

Jeff

Jeff here's my $.02 worth. You've messed with the emission control system by removing the primary cats when you installed the header less cats and when you alter the emission control system on a Boxster you really need to know what you're doing because the horror stories abound on the internet from owners who did that. Fabspeed, and others, make a set of headers that have sport cats built into them for you Boxster owners whose cars came with them. They are made to not affect the emission control system but add hp and torque by being less restrictive than stock but cost a lot per hp gain.
Porsche have developed a diagnostic tree so technicians can hook a computer to the car and go through a series of tests to determine the cause of issues with Porsches. The test specifically tests each component in a system such as the emission control system and pin points the faulty part. The codes you are getting are a part of diagnostic tree but they only point to a system and not a specific part. Trying to do a diagnostic with just the codes will have you chasing your tail and spending money uselessly. I got chastised on another forum for saying this but I speak from my own experience in emission issues when I say you need to take the car to someone who knows what they are doing, understands the diagnostic tree and has the equipment to run the diagnostics. Asking people, you don't know on a forum and who don't really know your car, to diagnose the problems is really farting in the wind.

Farting in the wind.....that's rich!!!:D

I'm kinda coming to the same conclusions also. I would love, love, love to get the Fabspeed headers but I just don't have that kind of cash at the moment. I did have an opportunity to get a used replacement stock header/cat but chickened out at the last moment worrying that I might just end up with another defective cat. I guess I need to explore that route again if I want to take care of this problem. This seems like the cheapest route.

I still need to make this car quieter though. Even before the headers it was too loud with the Borla mufflers. It was suggested to try the Dansk (sp?) but I'd sure like to hear it from inside the car before I pop for a different muffler. Anyone in the Charlotte, NC area have a Dansk on their Boxter S I could listen to?

Jeff

Ronster,

Well said!!

I go thru the same thing on some other car forums for the same reasons -- many people think that all DTC's are linked to specific components.

Regards,
paul...

Jeff I took my Boxster to the local muffler/hot rod shop where I live and had them remove it, cut the top off and torch through the baffles so the exhaust has a cleaner path to the tail pipe. The sound was rich and deep with no drone and no affect on smog or a visual inspection. A few months later I snagged a new Dansk Sport off craig's for $325 from a guy who wrecked his Boxster before he got it installed. The Dansk is close to the sound of my altered stock below 2-2.5K rpm then really opens up at 3.5K rpm. There is some drone at 2.5K rpm with the Dansk. In retrospect I actually liked the overall sound of my altered OEM better but the Dansk looks better with the twin pipes and I'm not going to pay to have it changed back.
After thinking more about your issues I think your problem is in the removal of the primary cats. Most guys opt for the cat bypass pipes that replace the secondary cats and leave the primaries alone. The cat bypass pipes also give a mellow growl that the secondary cats muffle.
Hope you get it straightened out.

Hmmm, sounds like a stock modified muffler might be for me. That droning is enough to drive you nuts!!!

I was all set to get rid of the secondary cats. Unfortunately just before I did it I realized that it was the primary cat and not the secondary that was making the nasty embarrassing rattle. The innards had come loose and once it got hot it sounded awful. I didn't have a choice. Oh well, no idea what to do now that will fit into my budget. I suppose a used header/primary cat is the best way to go at this point. I HATE EMISSION CONTROLS!!!!!

I am curious as to why only one bank is getting a cel though.

Jeff

I had a Borla muffler on my '88 BMW M3. It was so loud my wife wouldn't drive with me. It drove me crazy too, so I trashed it and went back to stock.

Ya, I think Horror-la Exhaust would be a better name. Of course if I were to wear a helmet all the time it most likely wouldn't be so bad:)

My friend at Autozone, who has had a long and varied history messing with cars, said that the easiest thing to do at this point is to gut my two stock primary cats and put them back on the car. He said that doing that will solve the back pressure issue even without the innards in the cats and hopefully get the motor running smooth again. Seems to me that I'm still going to get a CEL for the lack of difference in readings between the pre and post oxygen sensors. Does anyone know what gutting the stock primary cats will do from first hand knowledge?

Jeff

Still no idea what to do about the muffler. I like the idea of a stock muffler with the baffles removed but I will miss the sharp looking tips of the Borla. I wonder if I could get the tips from the Borla put on a stock muffler? Hmmmmm....

I had the muffler shop saw off the whale spout OEM tip and weld on a sport tip which I picked up new off eBay for $50 and it looks great.
If your primary cats are gutted you will get a CEL and it may or may not solve your back pressure issue. You might look around at places like Oklahoma Foreign and see if you can find a set that work for cheap. Good luck.

Get yourself a secondary o2 emulator. The secondary o2 only checks the performance of the Cat, because you have none of course it will code without some sort of fix!

Hey,

I took a quick look at O2 emulators online but didn't find one that said it would work with my car yet. I'm still concerned that the new headers have made the car run rougher though so I'm not sure that would be the best approach. It also said on the description of the CEL code that an exhaust leak could also cause my problem. I'm not exactly sure how to check for that. An exhaust leak would explain why I'm getting the code on only one bank of cylinders though.

I did manage to find a stock muffler for a Boxter S on Ebay for $165. I'm going to change that out when it arrives before doing anything more about the code. I did have a line on a used primary cat/header before deciding on the headers. I may go that route as all of the other options look like they could cause other issues or not resolve the current one.

How much would you all think my used Borla should go for if I sell it? Maybe I can include a set of shooting ear protectors in with the deal!;)

Jeff

A smoke test will find an exhaust leak and most of the time the leak will have a tick-tick sound kind of like valve clatter.

Most likely a stupid question but what exactly is a smoke test?

I've heard the ticking exhaust leak on other vehicles before and there's nothing that obvious occurring here. I did have exhaust leaks at the sleeves that go between the secondary cats and the muffler when I bought the car but it was a much less obvious noise. With that leak I could feel the exhaust escaping when I put my hand near the sleeve. Problem here is with that Borla muffler it's kinda hard to hear much of anything and be certain what it is. When I went to thicker oil I did notice the start up clatter died down to almost nothing though. As soon as I get my new muffler I'll get back under the car and give the headers a good close look. I'd really rather stick with the headers but I'm still thinking my best bet will be to get a used header/cat if I just want to not go through the hassles. I've got issues with all five of my vehicles at the moment and I sure would like to cross one off my list........and not by setting it on fire!!!!:D

Jeff

Here's your answer smoke machine wise.

Randy

Pelican Technical Article: Troubleshooting Boxster Vacuum Leaks - 986 / 987

Hey all!

Well I got a used Boxter S stock muffler from a place called German Recycling (or something like that) off Ebay for $165 shipped. Pretty good price I think. I installed it yesterday and I can now hear again! It may well be too quiet for me but I'm going to live with it for a while before I decide whether or not I'm going to remove the baffles. I'd also like to find an S in my area with the baffles removed before I go and cut anything. If there's anyone in the Charlotte, NC area who has an S with the stock muffler and the baffles removed let me know. Right now I've got the battery disconnected to reset the CEL though I'm sure this isn't going to take care of my problem. I do hear a little ticking that could be an exhaust leak so I guess a smoke test is in order next. What kind of places do this or do I need to take it to the dealer? Is there any chance of damaging anything with the CEL on? It did seem to run rougher at highway speed but that could just be my imagination. Is there any chance that the computer would lean out the motor too much to the point of damage? I'd like to take the car on a 2000 mile trip and I don't think I can get the CEL fixed before I go.

Thanks,

Jeff

CEL on could mean you'd probably be getting bad mileage and running that way for 2k miles probably wouldn't be good for other smog controlling items which could get expensive in the long run.

Hmm, seems pretty basic to me. You've removed the CATs and now you're getting the code that indicates a CAT failure. I've never heard of anyone successfully rigging the system to not trigger a CEL when they've remove the CATs. On my car, I have the Fabspeed muffler / headers with integrated CATs so that the car knows and sees that they are still there. I think that if you want to live life without the CATs, then you'll have to accept the CEL being on. On these modern cars, the flow restrictions from the CATs are fairly minimal - you don't typically gain gobs of horsepower through their removal.

-Wayne

I didn't remove the primary cats to gain horsepower. The innards in one of the primary cats came loose making a horrible racket and I couldn't stand it anymore. The headers were the cheapest way to go. I guess I'll see if I can find an inexpensive used drivers side primary cat/header. My only concern is the crap shoot of getting a used one that may be just as bad as mine is. Anyone have a known good one they'd like to part with?

Jeff

I see that I can get a new primary cat/header for around $400 shipped. They're obviously not OEM. Will these be okay or is it another instance of a low quality part I'm going to have trouble with fairly quickly or is a cat a cat?

Thanks,

Jeff

Update.....so I got the new used stock Boxster S muffler installed and I'm thrilled. It sounds great but I imagine it may be a little quiet for some peoples tastes. So now I'm getting around to battling the CEL. Unless I find a crack in the new headers or an exhaust leak at the head I'm going to have to get another cat to replace the defective drivers side one. I see online that I can get a cat new for around $400 but every one I see says it's for the 2.7 liter motor.

Is there any difference between the primary cats for the 2.7 and the 3.2 motors? Will these cats interchange?

Thanks,

Jeff

Final update......problem solved. Out of frustration I decided to put my stock primary cats back on the car and just deal with the noise one of them makes for now. While I was looking inside of the problem cat it looked like every thing was in tact. I expected that the material would be coming apart. When I tapped the cats on the floor each made sounds that were quite different. The good one was a thud where the bad one made more of a rattle. It came to me that maybe the innards weren't coming apart but that the whole cat insert was loose within the outer shell. So what I did was put the cat in my vise and squeezed each end just a bit thinking that might lock the insides in place. Amazingly enough it worked so I have no more rattle and no more CEL!!!

So if anyone is interested I have a set of headers with the relocated O2 sensors and a Borla muffler for sale. The Borla had a broken bracket on one of the mufflers that has to be repaired but other than that is in perfect shape.

Jeff