Ok i have a 03 lancer es....rrm piggy 2.5'' exhaust (tad too big i know) rrm highflow cat, rrm headers, injen cai, my engine has a slight stumble on low rpms around idle it kinda stumbles a bit as if missing. The exhaust also pops when i get off the throttle around 3k rpm, a few pops and thats it. ive noticed this for a while and i have no idea what it might be...i ran nitrous a few times (nitrous bad i know) it is the zex wet system. I did compression test and i got 1.180 2.165 3.167 4.165 ...i have no idea if this is good or not. and i just changed plugs and oil and it still stumbles a bit. any ideas?

 

Have you tried resetting the ECU? It could be the piggyback just adjusting to your conditions.

 

yeah ive reset it many times...same problem

 

oh and i forgot to mention im getting that mas code again
would that be the issue? I see no power loss at all...pulls like a champ 3k rpm + no driveability issues at all....since ive installed piggy it does that

 

Have you tried removing the piggyback completely? It could be the plugs so check those, make sure they're gapped right.

 

ive just changed them....whats the gap supposed to be?
i think its the mas but i dont want to spend 300$ and that not be it.nope havent removed piggy at all

 

It could be the MAF, have you been spraying the nitrous before the MAF or after it?

 

after about 6-8 in before TB

 

If you're getting a MAF code it could easily be the MAF, maybe it got damaged by the nitrous. I would remove the piggyback first and see if that solves it. No point in spending 300$ replacing the MAF if it's not the MAF.

 

i really dont want to buy a maf...the headers also glow red hot when driven hard.ill leave off piggy to see.

 

That's not good, if they're getting that hot something is seriously wrong.

 

exactly my point i really dont know at this point....what would make them glow?

 

The engine is running very hot which generally means it's running too lean (since gasoline acts as a fuel and a coolant in an engine).

 

thanks..ill check on it tomorrow..with piggy first...it runs very hot so hot the hood prop can burn you

 

That's not good, my old lancer never ran that hot even in the peak of summer, hell my subi doesn't get that hot.