Hey everyone,

I just picked up an Evo 8 MR from Chicago about a month ago. Had to take off the MagnaFlow Titanium exhaust and test pipe and throw all the stock exhaust parts on to get it through state inspection. After the inspection (took about a week of me driving around on the stocker), I put the Magnaflow back on and test pipe and the car was driving good until about 3 weeks ago.

I've been having problems at high boost (which is only occasionally) when shifting between 2nd and 3rd, 3rd and 4th, etc. with the car sputtering. Seems like it's almost not getting enough fuel or it's got a boost leak or something. When not moving, but just revving high, it's fine, no sputtering or spitting, just revs up and comes back down. The car has 269 Works cams with titanium valve springs and retainers, a Buscher 02 housing installed, Borla Manifold, Works P2 brain flash, and Magnaflow Titanium exhaust with Ultimate Racing Testpipe and Lower IC piping, and HKS Downpipe. Anyone else had this type of problem in the past and if so, what was the problem and how did you fix it?

I'm tempted to give up working on it myself and just take it to a local tuning shop, but I was just trying to see if I could get it figured out myself first. I'm thinking that maybe the injectors are clogged or need to be upgraded to bigger cc injectors (not enough fuel) or possibly the fuel pump is bad or something stupid like that. I've also heard that it could be timing related (which i'm definitely not going to play with!) or a boost leak. Any suggestions/ideas?

All help is appreciated. Thanks!

 

try changing out the plugs?

 

When mine started to sputter at high boost, I replaced the spark plugs and it fixed it

 

Pull the plugs, check the gap, let us know what it is, then try smaller. It sounds like ignition or boost leak to me, not fuel. What is "high boost" to you? If it just all of a sudden started you could have fouled a plug or a vac line could have come loose. My bet is spark. The revving in place doesn't matter, there is no load, you'll rarely if ever notice it unless it's really really bad.

 

beat ya :P

 

If its a stock ecu flashed you can try disconnecting the battery to reset the flash since it may have been compensating for the change in back pressure when switching exhaust. It's worth a shot simplest and easiest is always the best to start with.

 

 

Sweet. I appreciate all the suggestions. I think i'll try just disconnecting the battery first, then move to plugs if that doesn't work. I'll keep you posted.

High boost to me is almost WOT. LOL. It was happening when I hit a back road when I was with a friend of mine and then it's been happening every since then when hitting exit ramps or merging into traffic. I usually have to get on it hard to be able to merge.

 

ever figure it out man

 

Yeah, plugs were fouled. Car is running slightly lean and i think it's the works tune that is causing the plugs to foul. We are trying a few things to see if it will help, but if that doesn't help, then i'm going to have to get it retuned.

 

so the only problem was the plugs?

 

Yep. That was it. It's been running fine since I put the new ones in.