Check engine lite, on then gone

[SImp3]

I have had a check engine light ever since the install of my turbo. Even after my MPI install the light would come back on after a few days. I would disconnect the battery, clear the ECU and still 4 days later the cell would come back. Had a friend hook up one of those computers that fixes the cell (code that shows was bank 1 lean)and that would work for a week and the light would come on again. But the car ran great regardless. Last week the cell disappears and has not come back, despite me being especially hard on the car on purpose. I have tried to figure out why the cell has left and the only thing I could figure is that we went from 70 deg to 40 degrees in NY and perhaps the change in temp was afffecting one of the sensors. But this has never happened before so I am still unsure. Any suggestions out there.

Thanks

 

[blthlt]

Could be a few things. The obvious would be that your running to lean, do you have a wideband? It may be a faulty o2 sensor telling the pcm that your running more lean than you are. Try adding 2 points to the global analog value ie: if it's at a 6 make it a 8, this will richen you up some more and may make a differance. Let us know.

 

[SImp3]

No, no wide band, I have thought about making changes in the settings on the MPI Tuner. What still bothers me is the cell just disappears out of nowhere. I guess I will wait a week or two and see if the cell comes back on then make the changes. I guess I should be happy the damn cell is gone. Thank for the help

 

[Bigg Tim]

If you're throwing a lean code, then you need to richen the map up a little. Where are you leaning out at?

 

[blthlt]

I dont think he knows exactly without the use of a wideband. One thing to remember too SImp3 is with colder weather you'll have to richen up the map anyway. I really would richen up the map just a tad (lean is no good rich is ok) until you can get a good idea of what your a/f's are. Maybe do a datalog for us so Tim and I can take a look at them to see if there is anything we see that may need be changed.

 

[SImp3]

Now, I didn't know in the colder temps to run richer. I will change it thanks for the help
But stupid question, what does the colder weather have to do with running a bit richer. How does the colder temp affect burning of fuel. My only guess was the cold air is mixing with the fuel differently than in the summer with denser air? Is that it?

 

[blthlt]

yes, the cooler air is more dense thus having more 02 molecules so you'll need a bit more fuel to offset this. Correct me if I'm wrong Tim or anyone.

 

[blthlt]

yes, the cooler air is more dense thus having more 02 molecules so you'll need a bit more fuel to offset this. Correct me if I'm wrong Tim or anyone.

 

[FSRbikr98]

Colder air makes you run leaner, not richer, check your PM's.



On a side note, hows the forum doing, i havent been visiting as often as i should. Srtforums is taking up all my time!