I got my 2003 Evo 8 in Feb 2005. It had 3000 miles on it and ran perfect. I have added the AEM Short Ram, Turbo XS Blow Off Valve (w/ HKS Idle Stabilizer). 2 1/2"Cat-Back Exhaust. My service engine light came on at 15,000, saying 2 spark plugs were misfiring. I purchased Denso Iridium Spark Plugs, and Ralli Art Wires. It took a long time for them to come in. While waiting for them to come in I got the bosch triple platinum plugs, just to hold me over. After installing them I noticed that if I accelerated too fast (at about 4000 RPM) the engine would bog out, kinda "popping". I did gap them properly. Once my new plugs and wires came in I installed them. The "popping" and enging bog went away. Sometimes when I accelerate I still feel slight "popping" at about 5 or 6 thousand RPMs. I also noticed dramatic loss in throttle response. I will press the gas and the engine will rev but the will be no response. I thought it may be turbo lag, but I am not so sure. It does it in every gear in the low end. My baby just doesnt "feel" like she used to. I faithfully change my oil and filter every 3000 miles. and only use Royal Purple 10w30. Please help. What can this be and how can I fix it?
-Curtis

 

take the ralliarts out and switch w/stock. then check it out.

 

also, recheck the gap on your sp plugs.

 

my service engine light came on also took it to the dealer had an engine misfire. it was covered under warranty check to see if yours is under warranty

 

You ever get a tune? Getting an intake can screw up your AFR if you don't tune it right.

 

+1

 

OH good Lord, you made some terrible choices on things to put on your car. Let us review:

- AEM intake (without a tune = bad)
- TXS BOV w/HKS EIDS (bad)
- 2.5" cat-back (why why why? - doesn't hurt the car, but why 2.5"??)
- Bosch triple platinum (BADDDDDDDDDDDDDDDD)
- Ralliart wires (good items, but no reason to buy them)
- Denso Iridium (not gonna say bad, but why these instead of regular NGK?)

Ok, so we have a whole slew of useless or nearly useless mods here, so it's hard to diagnose what's going on with your car. Here are my suggestions in order:

1) Get a set of NGK BPR7ES spark plugs for $1.40/ea, gap to .26 and install those
2) Re-install stock plugs wires (just for now)
3) Re-install stock intake (use AEM after you get tuned)
4) Re-install stock BOV (sell and get a JDM MR DV or Forge RS)

If your car doesn't run properly after this, then you might have a big issue, but it will allows us to troubleshoot more easily. If your car returns to normal, then re-install the Ralliart wires and ensure things work fine. If so, then go forth and conquer while following my other suggestions. Also, sell that 2.5" cat-back if anyone will buy it, and then get a nice 3" exhaust (TBE preferable).

 

make sure you have the right heat range too.... 7 heat range is stock.

 

Wow, I really didnt know too much about all this before I started. Let me help explain some. First I have a question when you say tune...what is that and how much does it cost? I got the TXS BOV cause I thought it was good, and found out I needed the HKS EIDS after because I kept stalling at idle or when returning to idel after accelerating. I didnt know about 3" when I had my exhaust done, and so I just let the place do the work. The Bosch Triple Platinum were only temp to remove the messed up factory plugs until the Denso Iridiums came in. The wires I needed to replace and I couldnt find the stock ones except at the dealer, and I didnt think going to them was a good thing? The Denso Iridium plugs because I thought they were best, I didnt know about the NGK. What are they, where can I get them. I cannot re-install the factory intake because the parts were discarded when the AEm was put on (I have to get tuned). I do not have the stock BOV either because that was part of the factory intake. I dont think the BOV is an issue because I had the AEm, BOV, and exhaust on fine and was running perfect. It was when the plugs became an issue that I started having problems. I know you guys know way more then me, but its not like I can just up and buy all this stuff, and this is my everyday car. I know it is harder to help me like this, but it is all I can do at the moment. Thank you for your patients and help. What can I do besides the new plugs and stock wires? Does it sound like there is anything wrong besides what was said?

 

hey i kinda have the same problem.. i took my evo in to get the rear brake pads put on, oil change and put in sum new spark plugs at pepboys. the day before the car was running perfectly fine. drop off the car.. pick it up and im gettin on the highway so i step on it but at like 0.6 psi the car starts bogging and sputtering like crazy i freak out and go right back to pepboys. they run a dignostic on it and say my turbo went out cuz i put too many "gadgets" on the car.

on a side note.. the spark plugs i had ordered were ngk iridium plugs. (bkr7eix) they told me they were regular lancer plugs so they sent me to autozone to buy sum denso iridium plugs.

so any suggestions on whats going on?

 

dynoflash.com or turbotrix.com both do flashes(as well as other vendors on this site). ask around and search to see which fits your needs the most. your car is prob fine. try what warrtalon said, then let us know what the outcome is.

 

well, what mods do you have?

 

mods -

3" perrin downpipe, cat delete, exhuast
hks intake
hks ssqv bov (vta)
hallman pro rx manual boost controller (19psi)
walbro 255 fuel pump

and car was running absolutely fine with no tune or anything for the past 3 months when i got most of this stuff installed... and now all of a sudden with the whole spark plug change it started

 

Wow, I didn't know the "diagnostic test" could determine a bad turbo. Take it to people who know what they're doing.

 

Bah, hks intake, hks ssqv, and fuel pump without a tune - then paying Pep Boys to change plugs???? That doesn't really deserve help, but all you need to do is go get some NGK BPR7ES at Advanced Auto or Autozone ($1.40/ea). Gap them to .26 and try them out. BPR7EIX should work, too, but cost more. Whoever said those were for the regular Lancer needs to be shot.