So, the car came down with a bad case of hesitation/bucking recently and finally popped the p2261. I'm familiar with the bulletin regarding the vaccum tank so with that in mind I've:

Removed bpv and re-installed my Forge unit (oem was dirty;otherwise appeared ok)

Bypassed the vac tank(manifold port to front of solenoid)

Bypassed tank/solenoid(manifold port to bpv)

Checked for leaks near solenoid,etc


The car would make/hold boost when I parked it but the bucking persists; usually around 10 hg(vac). I'm going to check tubing,etc for obstructions. When searching I noticed that someone had used an inline check valve when their vac tanks failed-good idea but my "testing" has yet to reveal the culprit. Also wondering if a boost solenoid could cause this. Any help appreciated.

Update- car will NOT boost normally now(5 psi mode)

 

Post a pic of the setup.

 

SSlobalt- don't have a pic at the moment; "setup" was factory config. as far as vac lines/bpv when issue started(I'm schooled on the routing,etc). Car had been running/boosting fine; GMS1 (spliced).
Currently the Forge and the tank(only) delete are in place solely for the purpose of troubleshooting; tried one, the other then both. Cleared code but it came back during a cautious test drive. Same on/off boost + random bucking. I might have something going on with my vac lines or the solenoid. Appreciate your input as much as anyones on here. Btw I have NOT done a boost test,lol and I do not have a blow-off valve.

 

From what I've seen this code usually occurs when someone is trying to sort out a bov. I've also yet to see anyone having their bpv solenoid fail. The bpv is apparently malfunctioning and I haven't learned anything yet by swapping it out or bypassing the tank. Just looking for knowledgeable suggestions prior to throwing money at it. Other than the downpipe the car is all GM down to the air filter.

 

Sorry, my man. I've been down for a while with arthritis issues. Forgot about this thread. Did you find your issue?

 

Yes-thanks for asking. The issue has resolved itself either because of or in spite of my troubleshooting haha. I was reading your how to about a boost leak tester and planning a trip by Lowes when I decided to fudge around under the hood a little more. I removed the bpv vac line and ran some air thru it; removed/tested the purge solenoid and removed/recleaned the TMAP. Also lubed the o-ring and snugged it down good. One of these procedures smoothed everything out and the cel has gone away on its own-not sure which but at any rate yay.
Best guess would be TMAP

 

Good to hear!