noticed this the other day on my drive to columbus. Driving down the highway at about 3000 - 3500rpm's the car will all of a sudden the car acts like its loading up on fuel. if i let of the gas and it back on it will go away for a few moment then come right back? while it is doing it it sounds like a subby.. if i mat it to the floor, boost will build just fine, but car has O power

so far i have changed plugs and regap'd... checked for a boost leak, none found?
my mods are 3"turbo back exhaust, injen uicp, and injen intake, greddy profec II b

 

bump

 

Tell us more about your car. Model and year? Any previous problems that might be the source of your current problem, etc.?

 

its a 03 evo gsr. i dont know of any other problem before, i bought the car and drove it home, it ran fine on the way home, and started this the next day on my way to work.

 

2003 Evo's have issues with sputtering/misfiring. Are you getting any CEL codes? The specific code for this problem is P0300. Changing and/or regaping spark plugs should fix it, but maybe we can have some other 2003 owners chime in.

 

Yea thats the problem mine does it every now and then too.

 

Have to ask: Did you replace the spark plugs with the stock model ones? Just a thought.

 

Yea man sounds like plugs to me. Ant CEL's.

P0300 codes though are misfire code are generlly not related to actual misfires rather harmonics in the trans

 

well i chaned the plugs a couple days ago.. the car run great untill i am driving down the highway . its not throwing any codes, ran my code scanner on it.

its not really a misfire, its like hmm. some1 pulled a injector wire off. then once i let off the gas, and go back to normal driving its fine.. then at a another random time on my drive. there it is again?

i just when and got some cleaner for the maf, i cleaned it and am getting ready to put it back together

 

Here is what I noticed when my 03 had a dirty MAF. When you are going say 35 in traffic in fifth gear instead of it being a smooth rrrrrrr it is more like rrrrrrbrrrrrbrrrrr just a little bit of of studder per say. It bugged the hell out of me until I figured it out. The one thing I will say though was it was always fine on the highway. Good luck.

 

Weren't the dealerships reflashing to fix that? Mine is an 04 and it was reflashed for that.

 

I had the same problem every day, then I had the reflash, and it only does it once every 2 weeks or so now. I regularly replace my plugs and wires, the car has 40k on it. I would love to figure out what the problem is.

03 VIII
Mods
cone filter, AMS LICP and UICP, AMS Frontmount, Samco bypass valve, 3" turbo back w/hi-flow cat, and an AMS Tune.

 

One time I was just driving down the road when suddenly my car starts bucking like a pissed off bull trying to throw me the **** out of the car. Yeah, turns out my MAF sensor plug just came unplugged out of nowhere. I NEVER messed with it before hand. I later took it out and cleaned it and made sure it was plugged in REAL tight

Also, I fell victim to the oh so infamous P0300 after a timing belt replacment. When I would slowly accelerate, at about 3000 RPM's the car would start to misfire like a mother. If I backed out and tried again, it went away. But the misfire always came back in about 15 minutes. I changed my plugs and gapped them to .026 and the problem went away for good.

My car is an '03 and those are the only sputtering/misfire stories I have to tell. Hope I was able to contibute some sort of help.

 

I have an 03 and I solved the sputtering and p0300 by doing the following.

1) Dielectric grease on every electrical connector I could find.
2) Installed a grounding kit to all the primary ground locations and to the coil packs.
3) Went one step colder plugs and gapped them to .022.
4) Installed an HKS DLI II (just for a little added umph!)
5) Smoothed out any large gaps in the tune with EcuFlash.
6) Replaced the throttle body seals on the butterfly. (Huge difference in drivability)

I have not had a p0300 since all this was done. Also the sputtering stopped completly once I figured the gap needed to be less.

Paul

 

Ding ding give this guy a prize. Thats absolutely correct.