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Discussion Starter #1 (Edited)
I have a p0170 fuel trim code.

Freeze frame showed Ltft of 12.5

I have no vacuum leaks and a new MAF. Car runs and idles smoothly.
Power on acceleration seems low.

Secondary air injection looks like it's working fine.

I had the injectors bench tested and they are good.

Next test will be fuel pressure. I'm guessing that low fuel pressure
could cause a fuel trim error.

I have changed the fuel filter too. The fuel filter is also the fuel pressure regulator.
The fuel rail does have a fuel pressure damper

What is the correct fuel pressure measured at the check valve on the fuel rail?


I found the specs.

3.7to 4.2 Bar

54 to 61 psi
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