i just had my 88 fiero 2.5l tested for emissions and failed the idle part of the test. HC (PPM) limit 220 / reading 1055.CO(%) limit 1.20 / reading 9.23. Idle RPM 838. The cruise part of the test was passed - HC reading 98 / CO reading .01 .RPM 2430. I had been getting an intermittent check engine light for a couple of months before I parked it (got a daily driver to go back and forth to work till the fiero is fixed) and was getting a code 44. I also started getting a "bucking" while at highway speeds - like the car was not firing on all cylanders. It would come and go - usually going when the check engine light came on. I replaced the O2 sensor when the problem first started (i've always been told the check engine lights main purpose in life was to tell you the O2 sensor needed changing) but it didn't help - still got a code 44. I also got a code 35 when i pulled the codes today. I put in a new MAP sensor. Also found a broken vacuum line to the fuel canister and replaced that. The IAC has been replaced. The PCV valve works. I now get a check engine light when the engine has warmed up - sitting idling - which goes away when I drive. It comes back intermittently while on the highway. The "bucking" seems to be still there, though not as bad as it was this summer. I pulled the O2 sensor and it was coated with carbon. I am going to check the exhaust for leaks as it sounds a bit loud and I was told that this may give a lean exhaust indication. Any other ideas would be greatly appreciated.
One other thing - I thought when the HC and CO were high it meant the engine was running rich??? If so why the lean exhaust code???

Welcome to the forum.Try here.........
https://www.fiero.nl/forum/Forum2/HTML/046768.html

did you try changing plugs? how old is your cat?

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'86 Fiero GT

www.KylesFiero.tk
www.XoticRydz.tk

Welcome to the forum. I see that you are from CT. There are several members here on the forum from CT. Here is a link that will help you with your engine codes https://www.fiero.nl/cgi-bin/main.cgi?ECMCodes . You need to make sure that your engine is fully warmed up before having the test done. You also might want to replace the wires and plugs if you haven't done so recently. The reason for taking the test with everything up to temperature is to make sure that your catalytic converter is working correctly. If it isn't fully warmed up it will let more unburnt hydrocabons thru and cause it to fail the test. If you have the original catalytic converter, it also may be time to replace it. You can get a high flow model from www.rodneydickman.com or from www.fierostore.com . Good luck with your retest.

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[This message has been edited by avengador1 (edited 02-22-2004).]

thanks for all the ideas. started to check/clean the sensors and I think i got the culprit - bad O2 sensor. I pulled it out again and saw that the inside were coming out of the slot on the side of the sensor and if i shook it it sounded like a jingle bell. Has anyone ever seen this before ??? Went out and bought a new one and the code 44 is gone. The engine idles around 1000RPM's now but seems to wander a little. Maybe some new plugs and wires - mine are about 1 1/2 years old. The exhaust is original as far as i know (third owner). The only thing i see wrong with it other than a bit of surface rust is a small hole the muffler. The car has 81,000 miles on it - should I change the cat ??? Do the high flow ones make a difference???
Well, hopefully we pass....

quote Originally posted by 88fiero2.5se: thanks for all the ideas. started to check/clean the sensors and I think i got the culprit - bad O2 sensor. I pulled it out again and saw that the inside were coming out of the slot on the side of the sensor and if i shook it it sounded like a jingle bell. Has anyone ever seen this before ???

Yes, I have had that happen to me on several occasions and I finally went to a "good" (expensiver) place and got one, no problem since.

The small round hole in the lower part of the muffler is normal. It drains water out so the guts will not rust.

[This message has been edited by 84Bill (edited 02-23-2004).]