Car runs fine until I go over around 4300 rpm.
Then the car just loses power and the SES light flashes on and goes off again after I go under 4000 rpm.

Any idea what this could be?
I hope it's a cheap fix cuz I'm broke and that ain't no joke.

Would love to get it running normal again by Friday so I can go to the race in Sacramento on Saturday.

 

Okay, used freescan and got a "codec 55 fuel system lean"

What should I check for?

I do have a NOS Aux fuel pump on.

 

First thing to do is monitor the fuel pressure when the problem occurs. BTW, quit driving it till you get it fixed. If pressure is dropping, try removing the aux pump and try it again. Be sure your filter is new and check the tank check valve located by the axle to be sure it will breath. Check the pressure regulator for holes in the diaphragm by applying a vacuum to it directly. If all is ok but pressure still drops, it's time for a good fuel pump. If pressure is ok you may need O2's

Good luck

 

Fuel pressure is good. 40 normal driving 80 on the juice.
I didnt know the aux fuel pump only turns on when my nitrous system is on.

Turns out the left O2 is bad. The voltage reading would stay low all the time. But you know how it goes when you have a mechanic look at it. As soon as my friend takes a look at it the O2 starts working again. Took it for a ride went over 4k rpm and its still going strong.

So any suggestions on where to get an O2 with extension for headers?


Thanks
Oliver

 

I'd go with some O2 simulators.. that's just me though. You can mount those anywhere they will fit and you can leave the old ones in there as plugs.

 

I already have O2 similator that i'm not using.
But because I'm running nitrous I would like to know when I really am running lean.