I have the dreaded engine code:O

[Jeff396]

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

[ronster]

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

[paulv]

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...

[randy_k]

Originally Posted by ronster

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

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

Randy

[ronster]

Originally Posted by randy_k

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.

[randy_k]

Originally Posted by ronster

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

LMAO!!! Thanks, Randy

[Jeff396]

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

[randy_k]

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

[Jeff396]

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

[randy_k]

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

[Jeff396]

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

Jeff

[randy_k]

Originally Posted by Jeff396

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

[Jeff396]

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

[randy_k]

Originally Posted by randy_k

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

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

Randy

[randy_k]

What side is Bank 1? - mikefocke2

[ronster]

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.

[Jeff396]

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!

Jeff

[Jeff396]

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

[Jeff396]

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

[ronster]

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.