Running richer lately

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khhhhris's picture
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Chris
Nanaimo, BC

Jan 6, 2014
Running richer lately

Last week driving home my car gave me some wierd problem where is started running very rich... 10.0 on my afr (the gauge doesnt go any lower than 10). I limped it home, left it overnight and it hasnt done it since.

The problem I am having now is my car is running richer than before. I used to run 16-17 afr at idle and mid 11's to low 12's under boost. I can now see down to low 10's under boost and around 14.6 - 15.0 at idle.

My idle has not changed and my engine is still pulling the same vacuum. I have since replaced my cap and rotor, checked resistance of the spark wires, and attempted to clean the maf. The car seems to run ok but not as snappy as before. No codes from the ecu either.

Anyone have some ideas to point me in the right direction?

Lynx's picture
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London Ontario

Dec 23, 2009

Your wideband sensor is going bad.  Replace with a new one.

khhhhris's picture
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Chris
Nanaimo, BC

Jan 6, 2014

Hmm, hard to believe that cause I replaced it 3 months ago, I have a spare and will give it a go anyways. My last sensor went full lean when it quit though. Any idea how it would have went super rich that one night? I know it wasn't the sensor reading faulty then, I could see fuel spitting out my exhaust hah...

goshko's picture
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Quebec

Jan 28, 2010

did you check fuel pressure ???

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Erik
laval

Jun 10, 2012

Try another oxygen sensor, maybe the stock one has gone bad. If not you have a vacuum or boost leak. It happened to mine and the gasket from the IAC valve was cracked due to age.