Catylatic Converter question for Bruce

[acoen]

Bruce,

I know there is a method for checking for a clogged converter, but can you tell if a converter is clogged by Ca smog test readings. I have them if it would help (smog tested less than 300 miles ago). I'm slow to spool and the exhaust note seems a little more quite than my last factory stock WE4. The car runs good but seems to be a just a little sluggish out of the hole. Boost will build up slowly and starts to pick up as the car hits second gear and spin the tire through second then flatten out a just a little bit through the power curve (seems to build boost under much effort). My last car built boost effortlessly. The plugs are grayish white and clean, with 148psi across all cylinders. The car has 62k miles and is factory stock down to the exhaust tips, with no mods, factory chip. I've listened for exhaust leaks and it doesn't seem to have any. The car doesn't pop, fart or ping, no Knock, At first I thought it may be pulling timing for some reason...Man I wish you were closer to Fresno, there are no experts here in town or any where in the Central Valley for that matter. My last car an 87' WE4 would build boost much faster, by the time you were in second you were really pulling hard. As soon as this car starts to pull hard I hit second spinning the rear tire (peg leg) for 20-30 feet.

If I do have the converter tested do I need to remove it first?

Thanks.

 

[bruce]

I know there is a method for checking for a clogged converter, but can you tell if a converter is clogged by Ca smog test readings. I have them if it would help (smog tested less than 300 miles ago). I'm slow to spool and the exhaust note seems a little more quite than my last factory stock WE4. The car runs good but seems to be a just a little sluggish out of the hole.
If I do have the converter tested do I need to remove it first?

I'm not sure which Bruce you mean, but, I'll take a stab at your questions.

First, if you passed emissions with it in the recent past, then I'd say *chemically*, it's still working. But, inside the converter is a series of small passageways, that run lenghtwise. They can *plug up* with carbon, and become a restriction. When that happens, performance just fades.

Since it still seems to be good chemically, then the only way to test it with out adding a pressure port (ie welding), would be to take it off, and with a light at one end, try to see thru it. If you can't see much of the light, then it's carboned up.

Cadillac had a TSB out some years ago, about using a IR gun to measure temps in various areas of the converter, to see if it was plugged, but I've forgotten way to do that.
HTH

 

[gofstbuick]

Even though I'm not Bruce, can I put my .02 cents in any way? Tell you what, I'll just do it. There is a back pressure test to determine if the exhaust system is plugged. The temp test is really for cat efficiency. What are the emissions results from the most recent emissions test? Sent you PM, I can see your most recent emissions result if you call me or provide a license plate to me via pm.

 

[acoen]

I'm not sure which Bruce you mean, but, I'll take a stab at your questions.

Bruce, I'm sorry I thought gofstbuick's name was Bruce as well. I may not have many posts here but I'm on this site almost every day and have read several of your posts. As always you have some fantastic advice some of which I have used. I'm going to have gofstbuick check out my latest smog to see if anything is out of range. If that doesn't pan out I am going to remove the cat possibly this weekend and do the visual inspection as you suggested. The car runs good it just acts a little lazy, then again it may be the nature of the beast. Bruce where are you located, Buick guys are rare here in Central Ca.

Thanks again for the advice.

 

[acoen]

Even though I'm not Bruce, can I put my .02 cents in any way? Tell you what, I'll just do it. There is a back pressure test to determine if the exhaust system is plugged. The temp test is really for cat efficiency. What are the emissions results from the most recent emissions test? Sent you PM, I can see your most recent emissions result if you call me or provide a license plate to me via pm.

Gofstbuick,

Thanks you for the reponse, I sent you a PM with my License Plate number. I hope we can figure this out. Thanks again for the help.

Aaron

 

[acoen]

gofstbuick,

Thank you again, I sent you a pm with my work number. I didn't read your PM until after 2pm on Thursday. Feel free to give me a call any time tomorrow....I could sure use the assistance. I truly appreciate your help.

Thanks again Aaron

 

[#1HotRod]

...Fresno.

Hi Acoen, you in Fresno?
I've seen another very nice GN infrequently my area of Herndon/West, that you? BTW, gofstbuick is good guy & really knows his stuff. I had exact same problem about a year ago & was the cat. Don't wait to fix whatever it is, if is the cat you will soon rapidly loose so much power you'll get stuck out in middle of nowhere, I'm a witness to that.
If in Fresno area gimmy a PM or email.
Ray.

 

[Hacksaw]

If the converter is ok, the wastegate solenoid may be bad. I'm not sure how to check it, though.

 

[acoen]

If the converter is ok, the wastegate solenoid may be bad. I'm not sure how to check it, though.

Thanks Hacksaw, I will give it a check.....

 

[49-blues]

you can take the o2 sensor out- put in a pressure gauge ,crank over the motor and see what kind of back pressure you have-it shouldnt be more than maybe a few lbs.

 

[acoen]

That's a good tip....Thanks