Gasser help?! 15psi too much backpressure?

[azkcr]

My fiance` is having heck with her 02 TrailBlazer in Arkansas. I'm 9hrs away at A&M.
The guys there say it's a clogged cat bc it's making 15psi when revd.
How much is too much backpressure?

It won't go faster than 40mph and can't hit more than 2k rpms now.
It shifts fine and runs fine. It's just like it's not getting fuel.

I didn't know where to put this thread. Sorry mods.

If I was there, I would just unbolt the S.O.B., bash the stones out and be done with it... lol!
The dealer wanted $900 and a local shop said $250. I just want to know what the likelihood of it fixing it is.

Thanks in advance y'all.

[Jarrod B]

does or did she ever get on the hwy to run it ?

[azkcr]

Everyday.
Won't go more than 40. She's scared of getting a ticket for going so much under on the 70mph highways..l
I'm saying that it won't go faster than 40 and the rpms won't go higher than 2

[Jarrod B]

fuel pump? and ses lights? fuel filter? floor it and no change?

[jm03powerstroke]

yea its to much back pressure if its hitting 15psi. most tester go from 0-15 psi. at idle it should be around 1.5-2 psi, at 2000rpm it should be around 2-4psi and at 4000rpm it should be around 4-6psi. i have ran across a few clogged cat in the last few months some that wont rev over 2000rpm too one that the car would not even start. i also start the car with the test and 02s sensor out and see if revs up fine just another way to test it.

[azkcr]

It doesn't have any CEL lights or anything. New filters and everything.
I told her to get it swapped. It'll be $250. :/