Continous Problems...are they related?

[SeattleSy#1255]

Here is what my problems are...everything with a fresh tune up with proper parts, afpr, walbro, normal upgrades such as vacuum hoses etc....the normal stuff.......

my boost control is progressively getting worse with nothing touched or changed--- no matter what I do with the WG rod, ultimate settings, freeway driving or launching. the lose of boost control would best be described as its having a hard time building 16psi and is getting worse from 0-10 as well (having a hard time doing that too)...builds very slowly........however sometimes it will suddenly spike at like 20 or so.

other problem which i'm wondering if is related at all is i have a 3000 stall converter that since its in can't stall past 2400RPMs and can't get more than 4-5psi at launch....

with all this i'm thinking perhaps the cat is clogged very bad and is affecting all this. Could this be?

at the track times back up my concerns running a 14.0 at 97mph with a 2.0 60ft at best.......this is down from a 13.0 at 103 with a 1.72 60ft.

can anyone shed some light on these issues possibly being related such as the Cat is gone or perhaps not related at all???

TIA

 

[ItsMyTy]

yep it could be the catalytic converter clogged up/melted down

take it off and look inside is really the only way to check it, unless you have a backpressure gauge

 

[SeattleSy#1255]

..ok.....is it easy to take off the Cat or difficlut? only asking as i haven't been under there yet.

what am i looking for inside? Will it be obvious?

 

[ItsMyTy]

well its bolted on one end and clamped on the other so it's going to be a bitch to remove to inspect...

first do a quick check by banging on the converter with a small hammer and see if you hear stuff rattling around inside. if so then you know somethings FUBAR in the cat.

another quick check is to use a vacuum gauge (or your vac/boost gauge if you have one) and record idle vacuum reading. rev engine in park to 2000 rpm and record vacuum reading after it stabilizes at 2000rpm. the readings should be about the same. if the vacuum is quite a bit lower at 2000 rpm then you can bet there's an exhaust restriction, causing a higher load on the engine.

if you have to take it off, you'll see chunks of melted honeycomb stuff in the converter and if you look thru it you may see one of the bricks is clogged up completely not letting any light thru.

if you can see light thru the honeycomb bricks and they don't look melted from either side of the converter then it's ok.


remember, there's still a chance the cat isn't your problem. mine started rattling and the truck gradually got slower over a span of 6 months or so. when i put the new PTE turbo on i saw the front half of the old cat was melted down and clogging over half of the back brick in the converter.

 

[SeattleSy#1255]

well prior to trying to take it off i did the small tricks suggested....nothing unusual when hammering it and the 2000RMP test showed the same vacuum as did idle in park. I just don't know what to think?

 

[Syclone#2960]

I say it is your cat.$.02
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Lovely Wendie99