# , Reasons for 5KTQ to run rich?



## KARMANN_16V (Aug 25, 2002)

The 5KTQ that I bought as a beater has a problem (amongst other problems lol)
It starts right away and runs relatively smooth, idles around 900-1000 rpm but the exhaust stinks - it smells like it runs very rich...
That is happening regardless of the engine temperature and it does not smoke (black or blue).
I also have an emission test report and it failed.
Can you suggest to me what I should check? O2 sensor, coolant temp sensor, what else?
Thanks


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## KARMANN_16V (Aug 25, 2002)

*Re: , Reasons for 5KTQ to run rich? (KARMANN_16V)*

Bump


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## ejust (Sep 22, 2004)

*Re: , Reasons for 5KTQ to run rich? (KARMANN_16V)*

i would be wiiling to say O2 sensor. When they die, they tend to give the O2 computer a Lean reading so there fore itll tend to rich the mixture thinking the system is too lean. being as that you have a TQ, you should have the CIS (not -E) so the computer has control on o2 sensor only. I do believe there is a coolant sensor tied into that com as well. You can change the idle mixture with a 3.5mm tee handle. Theres a small hole between the black rubber air boot and the FI where the lines are bolted too. might have to drill out a small plug very carefully to make the mixture adjustment. Turn clockwise for richer/ counter CW to make it leaner. Also, if your exhaust stinks badly, it could very well be a sign that your catalytic converter is shot and needs replacing. A new O2 sensor and CAT should clean you emisions right up! Hope it helps ya out


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## StormChaser (Jan 3, 2000)

*Re: , Reasons for 5KTQ to run rich? (ejust)*

Agreed, do all the other stuff BEFORE you mess with the static mixture. 
1. O2 sensor
2. Cat
3. Check for and fix all the vacuum leaks (almost 100% chance there are some)
4. Full tuneup including: plugs, plug wires, cap , rotor, air filter, fuel filters (2), plus check & set timing and idle speed. Use only Bosh parts and no p[latimum plugs, they will make it run like cr-ap.
Then and only then should you even think about adjuting the mixture. And only do it if you have the proper tools. See http://www.humanspeakers.com/audi/timing.htm for details on how to do this. 


_Modified by duandcc at 9:02 AM 3/11/2005_


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## KARMANN_16V (Aug 25, 2002)

Ok, thanks guys


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