Air/fuel ratio spiking, backfires every other shift, dies in neutral
-
Driving home tonight my car started acting kinda weird. First it started backfiring every other shift, then the air/fuel ratio kept spiking to about 16 then dropping as low as 10, then balancing out around 13-14. Put it in neutral while turning into my apartment and it died out. started it up again, put it in the garage and shut it off. started it up again, and it was very sluggish to start idling. had to give it some gas to prevent it from dying. any thoughts? first time i've come across this issue.
09 wrx, perrin CAI, catless downpipe and an HKS BOV are all i have on it at the moment
-
Its your bov get a recirc kit or bpv problem solved
-
Are you tuned AT ALL?
-
-
The BOV isn't ideal, but if it's properly set up it won't do this. My guess is that the vacuum line from the top of the BOV to the back of the manifold popped off. It's not held on, and when it pops off it causes a pretty big vacuum leak that results in the exact conditions you describe. The other common leak on the 08+ WRX's is the throttle body to intercooler hose. The rubber end caps can come loose and cause a leak. The rubber pieces should be removed from both ends of the throttle body hose.
Those are the likely causes, but they may or may not be the problem in your case. It is also possible that your BOV is set up incorrectly and causing this. No matter what the root cause, it is definitely some kind of boost/vacuum leak that is causing this.
-
Sounds like a boost leak or vacuum leak. If you don't find anything awry in the engine bay (check all hoses/connections pre-engine), take it for a drive, see if you can notice any funny high pitched noises.
-
Found the problem.. ed you were right, it was a leak. turns out 1) there was a hole in the in one of my vacuum lines, and 2) the hose connecting my BOV flange to the BOV had come undone and popped off. that explains the lack of a "kssh" sound that i noticed on the way home today. moral of the story: don't try and troubleshoot your car at 2am with a flashlight.