VR has more HP when CE light on

Re: VR has more HP when CE light on (CannuckCorradoVR6T)

I had an incident that was relatively similar.
Every now and then, without rhyme or reason, my idle starts fluctuating, and my VR has a problem holding idle, without dropping right off and stalling. My check engine light comes on during these incidents also. When I am driving @ partial or full throttle the car feels great! Gearing down creates some neat backfiring sounds, and the idle (when it holds) sounds inconsistent, almost like I have a wild cam! During these incidents, the car feels awesome @ WOT. It really flies! My car usually feels good, but there is a noticeable difference during these incidents!
The only theory I can come up with is that my O2 sensor is misreading my air/fuel ratio, and assuming I am running too lean. Therefore attempting to correct the situation, my computer requests more fuel! This could explain the backfiring during gearing down, and the increase in power at WOT!
I don't know if this is correct, but it's the only theory I can come up with! I'm sure there are many more possibilities, that I'm not thinking of!
Just my 2 cents worth.
BTW where is Forest? Near Sarnia?

Re: VR has more HP when CE light on (1BadAzzVR6)

ahhhhhh... OK. I have been dealing with this same issue since the beginning of time. In the meantime I have done lots of stuff... cams, intake, chip. My car is more consistant though... idle is lumpy (a heartbeat miss... although it has brand new plugs, wires, and coilpack). My engine light hasn't come on for awhile, but the other day when it was really acting up it was coming on and then off again.
I took it by Strictly European, here in Toronto the other day... just to get them to see what codes came up and there was one that was odd... no signal from the o2. Ahemm... I just replaced it and had strictly install it.
I have also replaced the MAF... no effect, cam position sensor.... no effect, throttle-position sensor... no effect.
I will have Strictly really look the car over next week for a loose/frayed wire... but I am starting to think maybe a few things:
- wrong chip
- fried/partially fried ECU
I am going to check the first one this weekend, and verify it is right (if it weren;t though, I don't think the car would even run.)
In addition to the backfiring and other symptoms you described, my car also is rough/bucks on and off the throttle. ie - if I am in traffic and am on and off the throttle... there is no way to feather it... it is ON of OFF... like a rusty cable that is catching and suddenly letting go. Also, at very partial steady throttle the car is not consistant... power comes and goes without any rhythm. Last week, when the CE came on... around the same time, it was doing some MAJOR hesitating. It was like the MAF is disconnected... but the power would come on slowly as speed increased (although I don;t think increaseing speed has anything to do with it)... like turbo lag.
Anyway... so for the long post, but I have to explore this when I see people posting with similar symptoms of mine.

Re: VR has more HP when CE light on (alphazero)

Wow, that sounds exactly like what has been goin on with my car since i got it. My Check engine light used to come on and off with no sort of consistancy during cituations more so like whenever it wanted to. It turned out my o2 sensor plug was broken so i had it replaced and the ce light went off. But i have the same problem of a rough idle, almost so faint that the passenger doesn't notice unless i point it out. I have the backfire sometimes during downshifts and the jumpyness in traffic you were describing. Its like when you barely hit the gas it jumps then when you let off it jerks. And under slow acceleration its like i have 10 different turbo's kicking in. Im moving then it gets more power and pulls a little harder and repeats this about 10 times. kinda cool if you like getting jerked back in the seat a little bit at a time. I find it interesting cause we share all of the same exact problems. Please let me know if you figure out whats goin on