peter's canadian imola ZHP project

[az3579]

hey botond,

i swapped in the MAF from my coupe (which runs perfectly), and i have no change in behavior - it is still hesitating/bucking around 2500rpm under load in 4/5/6th gear. i guess now i need to start checking for vacuum leaks. also, i have an aFe intake on the sedan, OEM intake on the coupe. i wonder if it's not happy with that?

peter

It's doubtful that the intake is causing this issue, unless, of course, there's a vacuum leak somewhere in that area.
I also doubt it's a DME issue, but you can rule this out by unplugging the battery for a while. I think 15-30 minutes will do the trick. Need someone else to chime in and verify this, but because our cars are so electronically "involved", it's definitely a worthy troubleshooting step. The DME itself hasn't changed, so a DME won't just one day decide to make the car buck...

This sounds like a potential fuel pump issue as well, though there may be another issue due to the codes that were read. One thing that can affect both banks 1+2 is a vacuum leak; check the lower intake boot for cracks (might as well check the upper one as well). This is a very common issue.