Ok here is the deal. I just finished most of my mods. 3" greddy cat-back, jdm mr bov, K&N filter drop in, boost gauge, a/f gauge, and oil pressure gauge. Now I am seeing boost spikes at like 26-27 psi, so I am like WOW DANG. I ordered a hallman mbc and am waiting on it to get here next week. I am driving very much like a grandma as to not overboost like that cause I dont want to damage anything. Anyway last night, 2 days after the last mod was installed(3"cat-back), out of the blue the car started to sputter like it was misfiring. It did backfire slightly twice before I just turned the car off and waited a few minutes. Then started it back and it was fine. My question is it possible my ecu is not happy with the mods? Or maybe I have fouled a plug? I would think if I fouled a plug it would drive like that the whole time and not be ok now. Could me driving real easy also have something to do with it sputtering like that? Need some answers? Thanks for any help....

Scott 03' EVO 8

 

none of your symptoms make any sense from the overboost to the intermittent sputtering. something is big time wrong if the boost is that high, especially since you didn't even touch the boost system.

for the sputtering, try a fresh set of ngk bpr7es gapped to .026. part number #2023 at advanced auto.

 

You have an 03, did you have it since new? If not, how many miles when you got it. I think its hard to find an 03 which has NO mods on it, unless it was modded, stripped back to stock, and sold to you. You have been a member since last September, so I am guessing it has been used no?

 

Check your DV.. It might be installed backwards and the excess pressure blew an intercooler pipe loose thats thats not completely off...

FWIW the symptoms your describing sounds like a MAF/Boost cut, I saw that when my DV line was kinked on an HKS SSQV Blowoff valve and it wasn't opening at all.. Similar symptom if you have a DV installed backwards and not enough vacuum to open it at part throttle.

Also check the line you used for your boost gage.. Did you T it off the one on the valvcover (its easiest to get at) since it runs to the DV also...

 

That sounds like a great idea, and the possible fix!!

 

Warrtalon, yeah it doesnt make since. I have no IDEA why I would spike that high of boost. Only did that after the cat-back. With just the JDM MR BOV, and K&N filter It was 22-23psi peak then dropped to 18ish. I mean my mods are very light. I did buy a set of the NGK BPR7ES plugs and will change them tomorrow. My mbc will be here on tuesday and will put it in on wednesday. Is it safe to drive like I am as long as I dont push the turbo bast 22-23 psi? I really dont want to mess anything up.

Smokedmustang, I bought my 03' used. It had only 9000 miles on it when I bought it back in October. It now has 15,000. I was completely stock when I got it. Not sure if it was ever modified but did not seem so. Things under the hood looked normal. It was important to me to find a low mileage EVO so when I did I jumped on it.

MalibuJack, I did check the line for the boost gauge and yes it was T'd from the valvecover. I am not sure about being backwards. It looks normal to me, plus now the car is running normal again. I dont see any kinks? I guess I need to check it more closely. It kinda does sound like a cut but just for that brief time? Now it is running normal, I cant really push the car at WOT since I am nervous about how high it is boosting. I will be able to tell better when I install the mbc and dial it in for 22psi.


Warrtalon, just need to make sure I will be ok until I install my mbc. On 93 oct, and if I keep it under 23psi is it ok to drive for the time being or should I just park it until I can install the mbc and set it for 22psi? Oh and is it a smart idea to just go ahead and get a flash done with the mods I have? I was thinking that might have something to do with the sputtering since the flow has changed with the new exhaust. I wanted to do a flash anyway, just figured it would be the safe way to handle the light mods. Let me know what you think.

Thanks guys for your inputs, it is greatly appreciated. I just was worried I had damaged something by testing after the cat-back install and I saw 26-27 psi and I did that twice to make sure and was like man that is too high. I need to not do that. But figured since it is not spilling its guts all over I thought I would be fine until I get my mbc. But then last night that sputtering/hesitation happened and I got nervous. Anymore ideas what I could try? Thanks again....

Scott

03' EVO 8

 

I am going to get a Starbucks now Scott, it makes me think better, We will get your problem solved!!! Hang tough.

 

Ok well it looks like one of the pipes was lose and I guess I just missed it when it was dark last night. Hmmm oh well I will drive around some tonight to make sure that was the problem and see if the same thing happens again. But hey Warrtalon I do still need to know about my boost psi. Am I safe to drive as long as I keep it under 22-23psi? I will be installing my mbc on tuesday or wednesday. Think I will be ok by then? Also I do think that I need to go ahead and get the reflash for my mods. I think I am not going to do anymore mods. I feel like I will be happy with the setup I have. Just let me know, thanks again man.....

Scott

03' EVO 8

 

With the stock boost solenoid you shouldn't see anything but a rare spike..

The round portion of the DV should be facing sideways, if its facing up, then its on backwards.. odds are if you did that mod, and its on backwards, that blew off the hose or knocked it loose.. Don't feel too bad, I've seen at least a half dozen Evo's with them on backwards FROM THE FACTORY..