Subaru WRX Forum banner

Stage 2 Problems.

6K views 7 replies 3 participants last post by  hempy 
#1 ·
08 WRX Hatch Auto trans.

Stock other then

Cobb SF intake & Airbox
Cobb catted Downpipe
Access port - Stage 2 91 0ct + SF Map

The Issue at hand: Rpm Surging at low RPM & low load

When driving the car between 2000 - 3000 RPM at 10-20% throttle the Rpm will bounce up and down 100-300 rpm increments multiple time in a second ( E.g 2100, 2200, 2100,2100,2200). kinda feels like the first time someone drives stick the car almost bucks or jerks.

While the car is under load it performs as it should. Holds boost rpm everything very smooth.

What ive tried:

1. Was advise to check all vac lines from the intake back - all connected firmly.

2. was advised to check MAF and front O2 sensor are connected - Both connected

3. Was advised to check if the senors were working properly - Couldn't find info on how to test a Air Fuel sensor.

4. Was advised to swap back to stock MAP and test the car under low load low RPM and try to replicate the issue - not sure if thats safe for the car.

5. Was advised to try a pro tune as my fuel tables may be bad - no a bad idea but i would like to know the tune is the issue first

6. Swap the Air fuel sensor - have no as of yet done this as there are non available in town and they have to be ordered in, I would like to avoid spending 250$ at a guess as my sensor shows all its stats on the access port as working.
 
See less See more
#2 ·
Talked to cobb, they asked me for a bunch of Log's..Still waiting on their reply. I tried the stock map it seems to fix the problem, so it kind of leads me to believe for some reason my car just dosnt like the Cobb maps.
When the car is in stage 2 and running i can smell fuel from the exhaust.

So does anyone have any ideas?
 
#3 ·
i had a similar issue. i had the maf cleaned and that fixed the problem. u should upload the log here someone might be able to help. in my log the DAM dropped and this was evident in the log. also im no tuner but if u have those parts on and u use the stock map, thats prob not a good idea.
 
#4 ·
get an e-tune. cobb maps are horrible. its not your car, its cobb. and they'll never admit they have a problerm or they have to fork out billions$$$ in warranties. seems every day there is another bunch of people with problems running cobb ots maps.


seriously, get an e-tune. $100 for piece of mind.
 
#5 ·
Ive already made an appointment with TougeTuning in Toronto,a reputable Subaru shop (they run time attack, drift, drag cars) at most of the Canadian meets and do well. I was quoted 110$/h for dyno and 80$/h for road he said it will be 1 maybe 2 hours on the dyno then maybe half hour or hour on the road but they said the road tune isnt necessary it just smooths out the daily drive feel and im not building a "race car" so it might be a good idea havent really settled on that idea yet.

But until i can get there im doing minor things to try and remedy the problem. Came to my attention most of these problems come from bad sparkplugs, so thats the Saturday mess, one step colder plugs.

as for a Dirty MAF it cant hurt to try and clean it off, Thanks for the tip for sure!
 
#6 ·
togue is good. thats where i order 90% of my parts from. havent had them tune my car but i have heard good things. most part stores here in ottawa suck balls
 
#7 ·
Swapped the plugs. the rear driver plug is a bitch lets just leave it at that LOL. While i had the Cobb intake off i cleaned the filter and hoses the MAF looked nice and clean but i sprayed it down with some MAF cleaner and cleaned it up with some microfiber towels.

no improvement in performance. Looks like im gonna be taking a big old day trip to Toronto. Hopfully they can fix my issues with a tune. I just really dont want to drive all the way there for them to tell me i have a mechanical issue and they cant tune it till thats fixed.
 
#8 ·
O2 Sensor was the main issue. After i swapped the Spark plugs i got a missfire in Cylinder 1, so i did the standard problem solving for that and the O2 sensor came up as a possible culprit yet again . so i caved n dropped the 250$ and swapped it out...Misfire gone and Rpm surging is gone, been driving it for about 2 weeks daily to make sure everything is solid. Hit the snow real hard yesterday everything seems tip top!
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top