gmmusclecarman

iTrader: (20)

on my 93 v6 bird im getting about 12mpg. first i had codes for all o2 sensors running lean and egr solenoids 1,2,3. replaced egr valve and cleared codes. now i only have one code for the right o2 bank 1 running lean. pulled the o2 sensors and this is what i got.

passenger side o2 was completely black and covered in carbon while the driver side was completely clean. put them back on except on opposite sides to see if i got a code for the opposite side. instead i got the same code for the right o2 bank 1. when i take off from a stop it seems like it hesitates or falls on its face for a sec then is fine. it also idles a little rough. I also seafoamed the car awhile ago which didnt really do anything. Im not sure what this could be and id rather not just go out and buy new o2 sensors and have the same problem. could this be caused by a vacuum leak? anything to do with my egr valve? what do you guys think?

gmmusclecarman

iTrader: (20)

c'mon guys, nothing?

I just filled up today and got 8.6mpg, something is seriously wrong here. Ive been looking over the car and trying to figure out what the problem is. I noticed i have a small exhaust leak after the cat, but it is nowhere near any o2 sensors. I only have 2 of them which are on the exhaust manifolds. vacuum leak maybe? I dont hear any sucking noises though....

the car also seems to be running even worse after switching the o2 sensors.

gmmusclecarman

iTrader: (20)

well i changed the spark plugs, o2 sensors and made an egr valve block off plate today. the car runs perfect now. idles smooth, no more codes or stumbling, the throttle response is better too. I have a new fuel filter to put in tomorrow as well.

I ended up making the egr block off plate because im pretty sure the egr valve still isnt working even though i replaced it. I pulled it off and started the car with it still plugged in and its supposed to be closed at idle, it of course stayed open. so i said F'it and made the block off plate.

I guess we'll just have to see what the gas mileage looks like on this tank of gas.

jamezruiz

i also got a 93, but its a camaro 3.4l, i get around 12mpg in town *thats where i am at most of the time* and around 17-18mpg in highway. i have replaced my egr valve about 1.5 years ago, and its bad again. i have a ACtron Super SCanner so i check it all the time. my fuel to air ratio gives 15-16. which is rich, no o2 sensor codes though. fuel filter was replaced a couple months ago. there is probably a fuel leak somewhere. have u checked if u had a fuel leak? and has your mpg got any better?

gmmusclecarman

iTrader: (20)

My air/fuel ratio was around 14 before, not sure what it is now. I have not noticed any fuel leaks. I have only driven about 40-50 miles so far with the new stuff in so i havnt been able to check my mpgs yet. But i have noticed that the exhaust smells alot less like gasoline and overall the car is just running better that ive ever seen. i will post up my mpg results but it will probably be awhile.

I think the biggest issue causing this was my egr valve. I think the problem was more to do with it getting power than anything. I did a test with both the new and old egr valves to see if they were working. The egr is supposed to be closed while the engine is idling. so i pulled it off while the car was idling and with it still plugged in and it was open. so im guessing the wiring to it is shot. but anyway i just made a block off plate and just eliminated the system all together. I was a little weary about doing this though because i thought it might make the car run worse because at certain time when the egr is open the pcm is supposed to change up the timing. but so far the car is running great so i guess that fixed it.

I say do the egr test i did and pull the spark plugs and o2 sensors then go from there. good luck!