So today I bought a set of stock spark plugs from mitsubishi to replace them. The old ones weren't too bad but I'm at 8000 miles and decided to replace them. I'm currently running cobb stage 2 and megan racing turbo housing back exhaust. Not problems at all car has been running fine. I replaced the plugs and matched the gap to the plugs I took out. Went for a ride and all seemed fine until I got on it. As soon as I'd floor it the engine would hesitate almost as if the clutch was slipping and I'd hear pops out of the exhaust. I made sure the plugs were tight and the coils were seated. Another test drive and same thing. boost will go up to about 20 and the engine would hesitate when i got on the gas and it would accelerate very rough and much slower. So I decided to put the old plugs back in (that were running fine in the first place, I just decided to change plugs becuase I was kinda bored). Put the stock ones back in and the engine was behaving the same way!!! HELP!!! What is going on? Is there any trick to doing fricken spark plugs an on evo? I didn't touch anything other than plugs, i didn't touch hoses or anything. Someone please advise. All these recent stories of engines blowing up are freakin me out. Like I said my only mods are cobb AP stage 2 and tb exhaust. No WGA or MBC mods, No intake no UICP. Up until now my car had been running great.

_Michael

 

Note: We just finished a tune on an FP Red with the same stock spark plugs from the factory with over 10,000 miles on them. 26.5 psi and no break ups.

Check and make sure all coils wire plugs are snapped in. Make sure they "click" when plugging them back in.

How did you set the spark plugs in? Never "drop" them in. Lower them in with a magnet or spark plug socket, you could bend the electrode tip or break it off!

Other than that it is a straight forward job like you said but It is most likely something silly. Go over everything.

 

Well the best advice I can give is to retrace your steps.

It's always something you haven't thought of.

 

Well I tried checking the connections and retraced my steps. THe engine is doing the same thing. It starts up fine and revs smoothly. If I drive moderately I can go to redline with no issues. As soon as i get on the boost the car jerks violently not smoot like it did before. Does this sound like it may be a boost leak? I'm still hitting peak boost about 25psi. Could there be anything I'm missing. Its not making any wierd noises from the engine, It feels normal until I get on the boost at 4000+RPMS.

 

it might be the clutch...i had the hesitation when i put on my AP and intake and thought nothing of it...then i put on my cat back and it got worse...i took it to a shop and my clutch was goneee

 

Right now the orignal plugs are back in. I made sure all connections are good and checked to to see if any wires broke. I also reflashed again to my COBB stage 2 map just to make sure the ecu was set. Tried for another ride and now it's even worse. Idled a little rough but then as soon as I drove (very slow) the car started jerking and acceleration was very rough. I didn't go over 30. Took the car back to my house and code P0303 (cylinder #3 misfire) and U0167 threw. I don't konw what the U0167 us. So what now. At least I know its cyliner #3 but which one is #3 and what about it should I check. I'm really at a loss, whoda thunk spark plugs would be so compicated. I'm pretty sure it's not clutch, I don't smell anything like clutch.
-michael

 

U0167=Immobilizer Communications Error.

Why that would be part of the problem is beyond me.

 

maybe a problem has occured while you flash your car with cob why dont you go back to the stock ecu map and see what happens?

 

Check compression
Does it idle same? Check your maf too

 

security fuel cut or seriously dumb question check the part number on the plugs is the same.

no good if it is for another car meaning the Ralliart galant as they are the same motor but run a different plug

 

Dude, recheck your plugs for the rt kind, recheck gap for the proper gap for your yr...not the gap from you old plugs as measured when they came out. Sounds like you are gapped too close to me..when on boost the spark is blowing out under the pressure so you are losing spark..that would lead to popping out the exhaust with excess gas in the pipe, no power and would account for the msfire code. And be sure you have the wires on the plugs as suggested. Good luck.. M

 

I hope Im spelling this right put alittle dielectric grease in the #3 plug wire and reseat the wire onto the plug make sure you feel the snap or pop going onto the plug!!! You can buy dielectric grease at any autoparts store.

 

i thought spark plugs came pre-gapped. Thats what at least two dealers told me at the parts dept.

 

^^..I picked up some plugs from SCM and the gaps were off so guess they're not 100% pre-gapped

 

Make sure you have the coils on the right cylinders.