Quote:
Originally Posted by blue62
Sounds like the MAF was the issue.
Dirt even so small and fine that you can not see it can have an effect on the MAF.
They are very sensitive. Another thing that happens with them is that very fine dirt particles erode the coating on the hot wire. You can't see it with the naked eye. I have seen magnified pictures of the issue. Looks just like it had been sand blasted.
Yes Intake Air Temp. is affected by engine temp.
If your short term fuel trims stay at or near 0% they will eventually pull long term fuel trims down.
I think you stated you have 93k miles on the car.
MAF signals tend to slow down with age.
A new MAF "may" give you better throttle response and fuel mileage.
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Both long term fuel trims are about -4% now, but I suspect I know why, I am running on E10 fuel, it changed from E5 a few months ago. The air/fuel ratio for petrol is 14.7/1, but E10 is A/F 14.04/1, the difference is -4.4%. The ECU in built map is almost certainly set for 14.7/1, so would indicate a negative fuel trim.
I have a new MAF sensor arriving tomorrow, so will get this installed on Saturday. My Boxster ran great on the 10 miles each way to work today, so I am not going to worry about LTFT unless it works it’s way up to -10%.
Robin