Quote:
Originally Posted by ard
Andrew-
OP says it runs OK on cold start, but then when it warms up it runs poorly.... when cold the DME ignores AF readings from the (cold) O2 sensors, and instead runs a 'rich' map.... then, when it comes up to temp, it then uses the o2 sensors.
If the car has an air intake leak, this 'cold start rich period' would be fine...then when the DME uses the O2s, he is now lean. (becuase air is getting in that the DME doesnt know about...)
OP, dont look at CATs yet, lots of stuff can fool the DME into thinking cats are bad
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Yeh, I've been thinking about this very thing about how the O2 sensors don't get factored in until warmed up. Thought about the intake or vacuum leak thing too. Seems like intake manifold leaks are usually worse when cold and often close up a bit as the engine warms up. But then, I know every situation can be unique. Hmmm, guess it would have to be a leak in cylinders 4, 5, or 6 (Bank 2, per the P0430 code).
One thing I do need to do is pull the codes again, since I haven't yet after installing the new sensors. Probably nothing's changed, but it still seems prudent to do so.