99 Limited with 260k.

Got the dreaded P0300 & P0302 CEL code 2 days ago. On first start up, (cold) there is no misfire. Only starts after the truck is warm and 2-3 starts. This is what I have done with NO success.

Replaced the Coil (new one), changed out the wires (all) and changed the #2 plug and still have the CEL. Also completed a compression test of the #2 cylinder of 170psi same as the #4 cylinder. All fuel injectors taken out, cleaned and flow checked, all good. #2 injector connector noid test was good


Checked the MAF, for resistance this morning. 1.7kΩ which is out of range, 2.2-2.7, next step is to replace it. Cleaned the MAF and P0171 is now gone.

What I'm missing, any help would be great.

Anyone

I’ll be watching to see what others say about the misfire codes.

I can only speak to my experience with the P0171 code, which for me was caused by a couple pretty small and hard-to-find vacuum leaks. I did the “spray and listen” test and replaced several hoses.

If the MAF is off, everything is off. Can't really go much further in helping if you know you have a bad one. DENSO only, junkyard units work ok if money is an issue. I got mine off a V6 Camry, though yours is a 99 so different style.