alexisonfire

First off I have an Evo IX RS 20K miles. (Bought from dealer new.) It has been raining hard this whole week, today my car was running fine then out of no where it would start stuttering like if my car was not breathing, at very low RPM. I literally cant go pass 20-25 miles per hour. It just starts shaking bad. The car idles fine but when i put it in first it goes in slow then just starts shaking. The faster i go the worse the shaking gets. Im pretty sure it is not boost leak. I have that happen before and this is way different. I have installed new spark plugs but the problem is still their. My car has three bolts holding my exhaust manifold to the turbo instead of 4. Car is sounding like a suburu, it sounds like it is misfiring and random back fires while pressing gas. Can This be cause by exhaust leak? Tranny? Fuel/fuel pump? Spark plug cabels/coil? Please help..I have looked through this forum and could not find the answer. -Thanks

After Market parts.

3 "inch turbo back exhuast.
Injen ic piping and intake kit.

4g63er

If you had a wideband it would probably be reading max LEAN. I have seen similar symptoms before. Tuning issue. I have had this happen on VERY cold days (-10F) ... the car has to warm up or you cant move. It goes into "subaru" mode lol... it really does sound like an sti for a minute and then it stops if you stop applying load. This feels similar to what you get when you install a k&n intake with no tune, or no AFC.

gsXingU

iTrader: (3)

It sorta sounds like one of your ic pipes is not connected or blew off. Check all your ic pipes to make sure they are connected and all the way in the couplers.

alexisonfire

I will check all my ic piping check for boost leak. I know its not a tuning issue, car has had those after market parts for 7-8 month with out a problem. Im also going to connected it to a computer see what comes up in the next couple days. Please help.. This is my only ride.

SixOneNine

iTrader: (19)

Check spark plugs as well.

lurkerpika

iTrader: (8)

clutch slipping?

alexisonfire

Ive already replaced my clutch once, I have gone way faster on a dead clutch than 25 miles an hour lol. Clutch would not cause misfiring.

vishus7

iTrader: (13)

no check engine light?

check little things like leak at fuel pressure regulator or the vac line to it may be blown off.

spark could also be the issue.

if its not anything mechanical, it's probably an issue with a primary input sensor. maf is most likely the case, but your symptoms indicate that it may be a tps problem. hook it up to a scanner.

alexisonfire

Check engine light is on, and I have replaced my spark plugs yesterday and still the same problem. I will check my fuel pressure regulator and vac line ASAP. My car turns on and idles fine but when i I hit about 10 mph Car losses power and starts stuttering. The engine is definetly misfiring! How can it misfire when driving and not misfire when I rev it in neutral? Can this problem come from my MAF? I do have an intake installed and its been raining like crazy it might have got wet, can that cause misfiring? Im going to to check: ic pipes(leaks), Fuel Pressure Regulator(Vac line), Mass Airflow Sensor(loose/check for water), also check my Throttle responce sensor(loose/check for water). Where could I find the Primary Input Sensor? Time to go buy a couple monsters and get working on this car. -Thanks by the way for your guys' input it really means alot .

alexisonfire

Problem solved I had a boost leak, at lower IUC pipe and vac line on BOV came off. Thank you guys for your great support.