i think my car is backfirering because it like redlines at 4500-4600 under load and i dont know what it is.
what should i do to fix this? tune-up?

btw it only has like 50k miles

 

What do you mean by "it redlines at 4500-4600 RPM's"? Do you mean no matter what it won't go past that RPM range? Describe your situation more and you should get better responses.

Myles

 

optioptioptioptiopti

 

not always for sometimes when i race i hear this explosion underneth the car and te car hesitates and a little black smoke comes out
this is only when i floor it
it doesnt seem as fast anymore it like lost power
also sometimes when launching (m6) it hasitates

 

how can it be the cat? if u got no cat it gives u more power

 

Check your fuel pressure mine did the same thing backfire like you describe.My fuel pressure was too low turned it up and backfire went away.How old is your opti did you recently do any work around the opti involing water If so opti might be bad.Also check your ignition If you have an aftermarket ignition unplug and plug your stock onre in see if that helps.Good luck

 

When I bought my car it wouldn't rev over 4500rpm in third gear. It felt like when you hit the rev limiter. Anyways I changed the plugs and wires and the car came to life and I haven't had any problems since.