tuning problem??

**robs01formula88** · 05-25-2010, 05:26 PM

i have an 01 formula with cai, lts, catless y, and since i got a mail order tune it has been running inconsistant. sometimes it pulls hard and then other times not near as hard. and lately when i push the gas it is just like i hit the rev limiter at 2000 rpm and will not rev any higher. it revs in nuetral no problem. the plugs are whitish grey which makes me think its lean. fuel pressure is fine, but i have ruined 4 02 sensors in about 3000 miles. they are the corvette sensors. any help would be greatly appreciated. i have really hit a wall here.

**Frost** · 05-27-2010, 11:14 AM

Originally Posted by robs01formula88

i have an 01 formula with cai, lts, catless y, and since i got a mail order tune it has been running inconsistant. sometimes it pulls hard and then other times not near as hard. and lately when i push the gas it is just like i hit the rev limiter at 2000 rpm and will not rev any higher. it revs in nuetral no problem. the plugs are whitish grey which makes me think its lean. fuel pressure is fine, but i have ruined 4 02 sensors in about 3000 miles. they are the corvette sensors. any help would be greatly appreciated. i have really hit a wall here.

Unfortunately you can't really read plugs (by color) if they have been through normal closed loop operation of the engine.

It sounds like you have positive fuel trimming making WOT inconsistent. This can happen when a MAF reports low (on it's way out but won't code) for example.

How do you know the sensors are bad; have you WATCHED them switching and see that they always report low voltage or are you going by codes (which don't necessarily mean that they are bad, depending on the codes)?

Do you have a scan tool that will let you see real-time engine data?

**blackSS01** · 05-28-2010, 03:54 PM

Originally Posted by Frost

Unfortunately you can't really read plugs (by color) if they have been through normal closed loop operation of the engine.

It sounds like you have positive fuel trimming making WOT inconsistent. This can happen when a MAF reports low (on it's way out but won't code) for example.

How do you know the sensors are bad; have you WATCHED them switching and see that they always report low voltage or are you going by codes (which don't necessarily mean that they are bad, depending on the codes)?

Do you have a scan tool that will let you see real-time engine data?

Is there anything you don't know about tuning

But to OP, my car acted the same way with no codes but O2's going out and Frost was right, it was my MAF! Switched it and Bingo, money in the bank!