Thanks in advance I've been having problems with my 2001 Blazer I can't go more than about 30 mph and it seems low on power and starts to buck. I did have a mass air code which I cleared and cleaned the Mass air sensor. I also checked and I can't rev it up past 2500 rpm in neutral I was thinking that it maybe a plugged cat, does that sound right? also which one is it that usually causes problems the smaller first one or the second one.

 

Ok so I took the O2 sensors out to see how much back pressure there was ran better, so replaced front cat and runs 10x better now not sure if I should replace the main cat or not but seems to be running ok so maybe not.

 

there is more than 1 cat?

 

Yup, There is a pre-cat.

 

I'd do your main cat too - when it goes you'll be cursing 'I just FIXED this problem!!!'






bad cat.

(sorry couldn't resist)

 

My 98 only has one cat

 

my 2000 also has 1 cat.