if i have my pedal down all the way, once i hit around 55-60mph my car cuts out and starts to fall on its face. the check engine light then begins flashing until i let off then it stops after a few more blinks. i tried all sparks, wires, and coils, and nothing seems to help even by replacing them with new ones. any help ?

 

i have a 97 monte z34 that did the same thing just today replaced the maf sensor and runs like a top now...just some insite.

 

Had the same problem with my 03', turns out it was a clogged cataletic converter, GM warrantied it for me even though the warranty was over. Thankfully cuz it was over $1000 to replace.

 

over 1000 to replace a cat?!?!

psh, I'd rather just get a ZZP downpipe + a better cat for $200 and bolt it on.

goodbye u-bend, goodbye crappy clogged cat, and hello better performance for $800 less.

 

Probably would have went that route if I had to pay for it. It was actually $1100 but I think 75% of the cost was labor at the GM dealer. And I'm speaking in CAN dollars....

 

well the zzp downpipe would be ~$250 canadian...

that's still like 1/4th the price lol

 

Not suprised, GM parts are crazy $$$, maybe just in Canada, I don't know. I wrecked one of my rims 2 years ago, GM quoted me at $800 for a replacement, I'm not shi**ing you. 16" Diamond-cut cast aluminum.