new cat
 

Well I just got my Monte back from the dealer. My gas mileage has been down by about 2mpg the last couple months but I attributed it to hot weather and running the a/c all the time. Then I started seeing a decrease in power to the point it wouldn't pull even a small hill without downshifting. Took it in and the cat was plugged. Thankfully it fell under the "recall/warranty extension" The old girl flies once again, I didn't realize how much power it had lost because it was kind of gradual until it plugged up bad enough.

RE: new cat
 

How many miles did you have on it??

RE: new cat
 

I have 87,900 miles on it. I think it's been slowly going bad for about 3,000 miles. I'm glad they extended the coverage from 5yr/80k to 10yr/150k. While it was in they said my ISS should be replaced, but for $25 parts and $140 labor I'll try it myself.

RE: new cat
 

Wow...that's pretty good extended warranty.

RE: new cat
 

The warranty is only on the cat and installation and only if you car is in a certain year and vin range.

RE: new cat
 

Did you notice more heat comming from under the car and/or center console? I've noticed a slight heat reduction since I replaced my DP...

If you do end up replacing your ISS please take some pics note your process. Mine is acting up again and I really don't want to take it back to the dealer.

RE: new cat
 

what is a ISS? now you got me wondering... i have 160K on my 96 Z34 power and never seemed to be where i thought it should be from what i heard the stock performance times like 1/4 mile and 0-60 is there any other simptoms that could clue me in if this is the cause? i have a plan in the works to basicly replace the exhaust from the manifolds back, but it would be nice to findout if i should put a rush on the plans if it is a clogged cat.

RE: new cat
 

ISS= Intermediate Steering Shaft.

RE: new cat
 

The only thing other than lower gas mileage was the temp gauge ran one mark higher than I remember. No heat thru the console,etc.

I will take pics when I do the ISS. Hopefully I can find time in the next few weeks. It's been acting up for about 40k and seems to be getting worse.

RE: new cat
 

I had my ISS replaced (so they say) under warranty around 30K, 26K later it's right back where it was...


Pictures would be nice just to get an idea what/where this part is.