[Lyger]

sounds a lot like my car but be careful of the O2 sensor and be sure you got the correct one, i just cleaned mine and reinstalled it. ran like complete garbage for a drive cycle or 2 until it relearned itself.

lean burn chugs and is random even with the calpod switch off, sometimes it sputters enough that it can't maintain speed above 50mph in lean burn.

the plugs were gradually colored from dark #1 to tan #2 to cream white #3 telling me the cylinders aren't firing evenly so i am starting to think the 250k injectors are needing to be serviced next. for now i just leave the EGR unplugged, it seemed slightly worse with it plugged in. i plan to clean the intake plate when i clean the injectors, for now i'm just driving it.. getting tired after all the diagnosing i did and just happy it's getting the mileage it should.

 

[Kwaad2]

Have you cleaned your EGR plate? If you can reset codes, you could try unplugging your EGR valve, and see if you still have the issue. It's unconventional, but an effective way of diagnosing minor issues that the computer isn't picking up. (of course you are quite likely to get a code for that, but it shouldn't effect the car much)

I've driven it about 20 miles, and the fuel trim disaster is the same. I've got new plugs and injectors in the way. Should get them early next week. Praying it fixes my issue. I'm running out of budget

 

[Need4Speed]

I assume that the fuel consumption gauge is made from the injector pulse width. If that is the case, then what would make the injectors put more "fuel" into the engine, but the O2 sensor reports correct mixture after burning?

If your fuel pump assembly is damaged you might be sucking some gas from the bottom of the tank, and a little air from a cracked part above the gas level. If you were to assume a 50 50 mix of fuel and air, in order to get correct O2 readings your injectors would be open twice as long, and the fcd would indicate half the mpg.

Other possibility is a plugged injector. The cylinder would not have any fuel and would just be pumping a lot of air into the cat, possibly fooling the O2 sensor into thinking the mixture was too lean, and compensate by increasing the injector time, causing the two working cylinders to run really rich? This would also result in crappy mpg.

Running with the gas cap off or loose should result in a check engine light, the insight is sensitive. If I only click mine one or two clicks I will get a light, 4 clicks seems to work all the time.

 

[Lyger]

Have you cleaned your EGR plate? If you can reset codes, you could try unplugging your EGR valve, and see if you still have the issue. It's unconventional, but an effective way of diagnosing minor issues that the computer isn't picking up. (of course you are quite likely to get a code for that, but it shouldn't effect the car much)

I've driven it about 20 miles, and the fuel trim disaster is the same. I've got new plugs and injectors in the way. Should get them early next week. Praying it fixes my issue. I'm running out of budget

the bucking issues isn't from my EGR, connected or disconnected is the same and it isn't stuck open.