something wrong, backfires, constant cylinder misfires, help please

[raabguy]

I have a 06 wrx for about a year n a half now, not long after i got it the cel came on and it was 3 misfiring cylinders, brought it to the shop they fixed it k cool. Then, like 6 months ago the same thing! got it fixed again. NOW, like 2 weeks ago i was driving, i hit the gas hard in 3rd gear and it backfired big time, 3 big bucks and 3 big pops at about 45-50 mph, immediatly the cel came on, SAME THING (misfiring cylinders). They replaced my spark plugs, coils, fuel pump, and fuel pump harness to fix it. The cel is off still and it feels ok, but occasionally if i hit the gas hard it does the same thing, hard bucks and pops out the exhaust, does anyone know why this is happening

Ps. My mods are... Catback, catless downpipe, cai, boost control solenoid, and got it tuned at Metric Subaru on Long Island.

[JaySin]

Has anything been modified since the last tune? Is it a reputable tune shop? May be a bad tune or something to do with the catless DP...especially if it was added after the tune.

[raabguy]

Nope everything was added before the tune, and yeah the shop has a good reputation as far as i know, i was thinking that too that it might be the tune, it was a opensource tune. Maybe i should go to a better shop and spend like 500$ on a dyno tune? :/

[JaySin]

It could be the tune then. In my situation I used a stock Cobb map then had it dyno tuned/road tuned afterwards to work out any kinks...worked out perfectly, but cost a hefty $1,000 by the end of it. Cobb AP + ProTune = $$$$$$

My tune has been reliable for 3+ years now. If you're going to get a dyno tune seek out a good AWD dyno.

[Mikie13]

In the end, a Cobb tune and an Opensource tune will be the same thing: a map on the ECU that is tuned for Stage 2, so that shouldn't have anything to do with it.

OP, do some data logging if you can get a tactrix cable and laptop.