D@#N failed the EPA test
 

I took my '84 944 na into the Illinois EPA testing facility and failed. The point of failure was excessive Hydrocarbon emmissions.

So my questions are: :confused:

1. What are the likely causes?
2. Any advise on repair?
3. Any experience with this same failure?


Brian

Likely causes:

Missing\tampered with catalytic converter
Bad O2 sensor
Improper fuel mixture (AFM out of adjustment)
Stuck fuel injector (can cause over rich fuel mix)
Air intake restricted.

Try those for starters, they cause about 75% of the problems

AFJuvat

Brian...

AFJ's list is excellent...start with the easy things first...

New air filter and a can of Techron in the gas tank. Run for a hundred miles or so. Change the O2 sensor if it has more than 70K on it (just a rule of thumb) If you have the single wire unit, Pep Boys has the Bosch for $30 give or take.

Just before inspection, get down to about 1/4 tank of fuel and add two small bottles of gas line anti-freeze (isopropyl alcohol). Have car inspected. If it does not pass at this point, you either have engine management problams or as AFJ said, a trashed catalytic converter.

Let us know how you make out. Your experience adds to our knowledge base.

Bob S.

make friends and influence people
 

Buddy up with the service dept. guy at the dealership that does smog. Offer your firstborn

AFJuvat and Moneyguy1-- Excellent tips. I heard about using the low fuel and gas line treatment stuff. Just did not get around to doing it.

One goofy thing about the IL EPA (I like to refer to them as the Illinois EPA Nazi's) is that to obtain a waiver all work has to be done by a licensed mechanic. Work done by me does not count toward the waiver.

I will check the Cat coverter. There is no smell from the converter which usually indicates a bad converter. But the damn thing may just be a shell. If it is a bac cat converter I will change out that myself.

The O2 sensor has bee suspect for some time. After reading a couple of threads on this board I noticed my 944 idles a little high (about 1200 rpm). One thread indicated after changing the O2 sensor the idle speed dropped.

My first step will be to run a tank of high octane gas with injector cleaner. Second step will be to take it to my local (independent) Porsche guy and have him just replace the O2 sensor and check timining, and air mixture.

BTW where exactly is the O2 sensor located. I know it is on the exhaust system somewhere and I want to check to make sure it is connected.

Thanks for all you suggestions. They are better than my wife's. "Just sell it!".

Brian

High Idle coupled with excessive hydrocarbons? Same problem here a year back. Two things fixed mine, first I had several broken vacuum hoses. Second I had a small crack in my intake boot from the AFM to the intake. I could adjust some of it out with the AFM but not enough. Keep looking you'll find the answer. Additives and such are fine if you want to pass, but they are just masking a larger problem that is most likely robbing performance from the car.

Brian J you saying if a 944 idles at 1200 one of the probles can be that the O2 sensor is broke?

thanx
Nipzz

Just beyond the point where the two halves of the exhaust manifold join, there is a welded flange on the top of the pipe. The O2 sensor is installed there, vertical, facing up. When you remove the wires, tie a piece of string to the end in the engine compartment before threading them down. That way, after install, the the wires will take the same path up, avoiding contact with hot exhaust parts. You will require a 22 mm wrench. My best luck has been carefully threading the wire through a box wrench. Soak the old unit with penetrating oil and let sit for a few hours; if it won't budge, try running the engine for two or three minutes, shut iff and squirt the old unit base with p-oil and try again. (don't burn yourself!!!)Remember, you are working upside down and "righty-tighty, lefty loosy" can be confusing. Even after all these years I take a nut and bolt under the car with me so I can verify I am turning the item in the right direction.

Also try another line. My friend's mom has a 951 and fails the test once in a while. She just gets back in line and goes to another station and passes. I think some people are just looking for handouts.

Good luck.
CD

Maybe in TN. In Illinois the cars are tracked by license number. Cannot have the car tested within 48 hours. Only one testing station in local area. The next nearest station is in Chicago 300 miles away.

Brian

Doesn't anyone like Dealer service people? That makes me a saaaad Panda:(

I have no problem with dealer service people in general. I take my Sonoma to the GMC dealer to get is serviced. My wife takes her Grand Am to the Pontiac dealer.

It is the local Porsche dealers (we have two) that I have a problem with. They charge you $100 to walk through the door and treat you like you don't know squat. The dealers do multiple car lines, Porsche, Audi, BMW and Mercedes. My guess is that they deal too much with people who have more money than car smarts. There is a local guy whose primary interest is building and racing stock cars. Not a real profitable business so to augment this business he services BMW, Mercedes, and Porsche because he knows the rep of the local dealers. He has been doing this for over 25 years. Plus his labor prices are half and he will will parts not provided by Porsche (i.e. Bosch).

Don't misconstrue, dealer service departments are many times reputable and dependable. But don't discount the independent service guy.

BJM

Just an update to my situation.

Today I got my 944 back from the mechanic. $328 later the problem is fixed (I hope).

He replaced the distributor cap, rotor, and oxygen sensor. The distributor cap center post was gone, the rotor was pitted due to arcing between the center post and the rotor. The oxygen sensor was the orginal one from the factory.

Also the plugs were removed, cleaned, and re-gapped. The fuel mixture was adjusted to factory specs (someone along the line played with them) and the idle speed was adjusted (again someone adjusted it on the cam).

So I picked it up on my way to work this morning and was amazed with the increase in acceleration and smooth running. On my way I thought the tach was busted. Cruising at 80 mph on the interstate the tach only read 2900 rpm. Before the repair the tach would read 3200 rpm at the same speed. But when I caught up with the traffic jam I realized the tach is just fine.

Turning onto a side road to get to work I need to execute a left turn onto a busy street. After pulling away from the stop I popped it into second and hit the gas. The rear end squeeled and fish tailed into traffic.

Fathers, hide your daughters cause I'm back on the road

And yes, the answer (yet again on this bbs) was:
BASIC MAINTENANCE!!!!!

No car should be driving around with ignition components in that condition. Cap and rotor arm are 15k service item replacements.

Finally, I have resolution to my problem..http://www.pelicanparts.com/support/smileys/ura.gif

After the third time taking to my local guy that has done all the work on it before and I trusted him. He gave up with the excuse that the EPA station had bad equipment. He replaced the distributor cap, rotor, and oxygen sensor. Adjusted the injector fuel mixture and found out someone tweeked the electronics for the fuel mixture. Both were set back to factory specs.

Also he timed the car using the same timing equipment he uses for his professional stock car. Can't get finer than that.

So, long story short...http://www.pelicanparts.com/support/smileys/yawn.gif

I took it to another guy locally that works on everything not American. I have seen several Porsches at his shop so figured ne knew something 'bout them....

Seems some dumba$$ removed the catalytic convertor and installed a resonator. Why the first guy missed it I'll never know. Without the cat-convertor no matter what was done the car would not have passed.

Now $900 poorer my baby is back on the road again http://www.pelicanparts.com/support/smileys/drummer.gif

Plug wires are very expensive.....adn I'm gonna look into cap and rotor prices....wish me luck.....

I can say that my car runs at about 3k rpm when doing 80, so it may be just ok there......if that's an indication...

I said it before and I'll say it again...

Occam's Razor: The obvious and easy solution is usually the best one.

Thousands of dollars of troubleshooting and new parts is no match for preventive maintenance and checking the easy/obvious.

Yep. And then you find out the previous owner replaced the computer with the wrong unit, and you've been trying to pass emissions with a mix of stock and aftermarket chips.:rolleyes:

Yep, that was a big part of it. The TPS also was out of adjustment, and the idle-adjust screw had been replaced with something that maybe the mechanic found in his pocket, because it sure didn't belong there.

Not to mention the myriad of vacuum leaks I discovered, to include BOV, fuel breather valve (it was totally shot, .500" tear in the diaphram), idle control valve, etc etc etc. I did a complete tuneup on the ignition components too. I also discovered the PO was running a 3 bar FPR with that hodge podge mix of computer chips, so it was small wonder that it was failing so miserably. And don't forget he'd punched the catalytic converter and hadn't told me.

Runs like a scalded cat now.:D

In fact, I've had four people try to buy it in the last month. Two were serious, and one is content to wait until I'm done with it.

How much would you pay for just the wires? That is new wires with the screw in tips that fit the BERU ends you already have?

Colors too!