new member with question

[nick 6]

Hello buick world. I have been reading posts for a couple of years now,(thanks for all the great information) and I finally need help at wot when I reach full boost (set at 22 psi) it makes a sound like it cant get enough air then the engine bucks (like if 1 cylinder is not fireing) then boost and rpm drop even though I am still holding it at wot. This problem has occured at lower boost levels also. My scan master read 813mv and 3.3 kr.Does this sound like a bad turbo. and if so why would the rpms drop too Also the car never dies once I let up on the throttle it acts fine. Thanks in advance for any help

 

[QUIP'6']

catalytic convertor?

 

[nick 6]

The car has a newer cat on it. But i do suspect it might be a problem. The shop that put it on said it was a HIGH FLOW unit but comparin it with the stock one it is a lot shorter. Just waiting to take a broomstick to it does this sonund like an excessive back pressure problem? Thanks

 

[nick 6]

anybody else?

 

[QUIP'6']

clogged air filter or you can check maf sensor and coil pack and control module

 

[Gary Wells]

The car has a newer cat on it. But i do suspect it might be a problem. The shop that put it on said it was a HIGH FLOW unit but comparin it with the stock one it is a lot shorter. Just waiting to take a broomstick to it does this sonund like an excessive back pressure problem? Thanks

----------------------------
The aftermarket hi-performance cats are shorter in length, as they are generally modified from a cat designed for another system/vehicle, and cut to length by the seller/reseller for the individual downpipe & exhaust system. I have a Quad Air (Red Armstrong) shorty that is an exact fit between a THDP & a hooker Cat Back system running Hooker Aerochamber muffs. It was worthwhile to me to order another one to be used as a test pipe after the hammer drop test. You will notice a difference if you hollow it out or you opt to run a test pipe. A little louder & noticably more get up and go. HTH

 

[Lee_Burough]

Hello buick world. I have been reading posts for a couple of years now,(thanks for all the great information) and I finally need help at wot when I reach full boost (set at 22 psi) it makes a sound like it cant get enough air then the engine bucks (like if 1 cylinder is not fireing) then boost and rpm drop even though I am still holding it at wot. This problem has occured at lower boost levels also. My scan master read 813mv and 3.3 kr.Does this sound like a bad turbo. and if so why would the rpms drop too Also the car never dies once I let up on the throttle it acts fine. Thanks in advance for any help

A couple things that come to mind here....

First, what volume of air flow are you seeing on the scanmaster? (MAF air volume will give you an indirect measure of the CAT and its efficiency.)

Second, what gap are you running on your plugs?

Third, What does it sound like when, "it makes a sound like it cant get enough air then the engine bucks"? (if you have a stock turbo, you're at its limit of efficiency already, is that what you hear?)

Fourth, do you have KR only at 22 PSI, or is KR there at the lower boosts settings when it bucks?

Fifth, Relative to the KR, what is your O-2 reading at that time? Said another way, what operataing conditions did you notice 800+ O-2 voltage? (i.e., what gear, what RPM....?)

I would still look at basics to find the cause of this problem....Plugs, wires, coil/ignition, fuel pressure (45PSI plus one pound of pressure for each pound of boost), top engine cleaner, injector cleaning, the whole engine operating system.