need help

hi there everybody......im new here to the forum.......well i have a 91 3000gt vr4 with a k&n air filter, rfl blow off valve, and y pipe. the reason im posting is because my car laggs at 4k rpm on every gear and then sometimes it back fires. i am not really sure what might cause the problem so i need help. any suggestions of what might be causing this problem?

Your airflow sensor may be defective or you may have a leak somewhere in your intake causing your car to run rich would be my guess.

I bet your RFL is leaking. Why do you have one if you dont have any other mods?

Why do you have one if you dont have any other mods?

why not? b/c its "Really Freakin Loud"!

would spark blowout cause a lag/hesitation?

^I'd think so, but I think tal skinny's right in saying that it may be leaking... I mean open loop's usually cause the car to run rich between shifts and most require tuning in order for the BOV to actually function w/o problems...

Miles and maintaince?

Boost leak, whether from the BOV or somewhere else could be the issue. The BOV would cause rich conditions and backfiring possibly even stalling issues.

How are your rpms at warm idle? Do they fluctuate or stay steady?

When you say it lags at upper rpms, do you mean like an on/off hesitation, or it simply continuously lags?

I vote crappy BOV. The Turbo XS RFL BOV has been known to have problems every once in a while. I'd suggest getting an HKS SSQ BOV.

Or just put your stock one back on and see if the problems go away.