I have done some searching and have found a lot of useful information but had a few questions that need to be answered.

I recently purchased a 2003 Evo, was getting a rough idle when driving, service engine light would flash, and service engine light would constantly come on then turn off after a few days, and car would constantly stall/idle rough. The car was purchased with an HKS SSQV VTA and I read that the HKS was not good for the Evo so I purchased an MR BOV, stock UICP, and an ets intake. Everything ran fine for a day until yesterday. Service engine light flashed then stayed on, when I am stopped at a light attempt to go and press the clutch in the idle jumps between 200 and 1000 and sometimes stalls. Also when I am on the highway it feels like the car looses power and makes a sputtering sound. I let off the gas and it stops but comes back at a later time.

I have checked all the piping, no leaks, cleaned out the throttle body and all those seem to be fine. I read that the IAC may be the issue but where is this located? About to go to Autozone and see what codes it is throwing but any other info or suggestions would be greatly appreciated!

Sorry for the long post and thanks in advance!

Mods: 3" TBE, ets intake, MR BOV. (Does have a turbo timer installed from previous owner but I dont use it)

Thanks

 

did you reset your ecu when you changed back over? thats always worked for me.. let idle for a bit it should work it way out... But it is pretty easy to take it to the auto store and get the code . Let us know what you find.

 

codes would be extremely helpful man. Is there a boost gauge in the car if so what does it read when it is just idling

 

I reset the ECU by disconnecting the battery when I switched out the BOV... Just did it again to see what it does. Took it too Autozone and it is throwing the P0300 random misfire code. The boost guage reads -.9 when idleing. The plugs were changed out 2-3 weeks, torqued down to 18 lbs, and gapped to .26. Any ideas?!

Thanks

 

Maybe your sensor going bad...

 

tps sensor????

 

Reset the ECU and the CEL went away...still flashes at times on the highway to I think it is still mis-firing?! Anyway to test the TPS or do I pretty much have to try a new one? Also, can someone tell me where the IAC is located, please? I heard that has worked for some?

Thanks for all the help

 

i would get a tune IMO just to make sure everything runs right.

 

I'm having similar probs with the idling..... the car was misfiring under high boost situations..... Got it tuned at DDP in Vegas... He suggested recirculating the BOV too and I'm waiting on the fitting as I write this....

But what floored me was this..... I was running NGK BKR7E .... Doug told me to get a set of NGK BR7ES and it was the best $12 improvement in the way the car ran. I mean everything felt smoother.... accel ... decel..... high boost NO misfires at all......

The first set of plugs were pretty much brand new when i pulled them out..... so give it a shot for $12. I could not believe the difference.

Mark