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If I start my car after tuning it and let I come up to temperature and idle for 15 minutes everything is great AF Alpha lean is 0 and 02 (Lhs) is 0.00

After driving around and coming to a stop for a prolonged idle AFR's go to mid 13's. AF Alpha lean is still 0 and 02 (Lhs) is 0.20 or any number >0.

My O2 sensor is making it run rich. Now if I turn off 02 in the feedbacks and it displays 0.00 in the gauges and stays that way I never have a problem.

Can anyone help me?? Whats the deal?

Two40sPlease wrote:If I start my car after tuning it and let I come up to temperature and idle for 15 minutes everything is great AF Alpha lean is 0 and 02 (Lhs) is 0.00

After driving around and coming to a stop for a prolonged idle AFR's go to mid 13's. AF Alpha lean is still 0 and 02 (Lhs) is 0.20 or any number >0.

My O2 sensor is making it run rich. Now if I turn off 02 in the feedbacks and it displays 0.00 in the gauges and stays that way I never have a problem.

Can anyone help me?? Whats the deal?

I'm a bit confused, but I run richer then 14.68:1 at idle sometimes. I'll run like 13.6:1 sometimes during idle. Why? I don't know maybe cause there is load on the engine like the AC. If that's your only concern I wouldn't worry about it.

modulation wrote:

Two40sPlease wrote:If I start my car after tuning it and let I come up to temperature and idle for 15 minutes everything is great AF Alpha lean is 0 and 02 (Lhs) is 0.00

After driving around and coming to a stop for a prolonged idle AFR's go to mid 13's. AF Alpha lean is still 0 and 02 (Lhs) is 0.20 or any number >0.

My O2 sensor is making it run rich. Now if I turn off 02 in the feedbacks and it displays 0.00 in the gauges and stays that way I never have a problem.

Can anyone help me?? Whats the deal?

I'm a bit confused, but I run richer then 14.68:1 at idle sometimes. I'll run like 13.6:1 sometimes during idle. Why? I don't know maybe cause there is load on the engine like the AC. If that's your only concern I wouldn't worry about it.

My car was having the exact same symptom except I don't have ac. BTW ac shouldn't affect it, Its the 02 sensors job to keep afr's at stoich despite engine load while in closed loop.

My short term fix though is to disconnect my 02 sensor and turn it off in the feedback switches. Running in Open Loop my car car acheives better afr's that are closer to what I'm shooting for in the map.

also while checking which cells in the fuel map have O2 sensor feedback flags set

perhaps start with them all off and then gradually enable them in areas of the fuel map and monitor their effect.

going from O2 sensor feedback in one cell, to disabled inthe next cell could cause rich then lean conditions

also keep in mind O2 sensor feedback is dpeendent on temperature which is why it would run fine (no feedback) whilst cold

Matt wrote:also while checking which cells in the fuel map have O2 sensor feedback flags set

perhaps start with them all off and then gradually enable them in areas of the fuel map and monitor their effect.

going from O2 sensor feedback in one cell, to disabled inthe next cell could cause rich then lean conditions

also keep in mind O2 sensor feedback is dpeendent on temperature which is why it would run fine (no feedback) whilst cold

Thats the weird part all this fluctuation over time is occuring while the engine is at operating temperature(75-94 celcius). And if O2 sensor is dependent upon temperature there must be a map for that, Which one is it?

I had the same problem over and over again... the last time i "re-tuned"it i simply left the o2 sensing off and havent had any more problems. AFR's are still solid after 2 months!