Clogged cat can cause low vacuum.

 

The 11.2 is at idle. It says it supposed to be around 18-20. My catalytic converter does look like its getting hotter than normal. Also looks like its getting rusty maybe from the heat of it being clogged Im guessing?I don't know what my bank 2 Stft and Ltft are supposed to be at idle but they don't look right compared to bank 1.

 

What happens to the vac reading if you rev it up and hold it up?

 

I used freeze frame data I didn't use a vaccum gauge. I will try to pick one up and see what the readings are.I was going to replace the cat in a couple of days but isn't it pointless if there's something else wrong with the truck? I don't want the cats to go bad again because if that happens i'm just going to get fake o2's and straight pipe the catalytic converters.Seems like this truck has been a money pit so far since ive owned it for a year but the more money i throw in it the more new parts are going on it so guess its not that bad.

 

First thing I though of by reading the title was clogged cat. Happened to me on a different vehicle. You said you replaced one cat, why not the other? I'd suggest at least having a muffler shop do a pressure test. They'll usually do it for free, knowing they'll get to charge you to fix the problem they might find (kind of like free batt/alt checks).

 

my 96 has the same problem, i replaced the regulator and the pump, plugs, wires, no codes for any thing, and no difference in performance. monday, im gonna run open headers and see if that makes a difference. ill let u know

 

dissconnected cats. sounded cool, but no difference

 

I replaced the pump basket and now all is well.

 

what’s pump basket?

 

That post is from 11 years ago. Do not expect a answer. Check the dates your replying to as many posts / posters are one and done.
Pump basket is the in tank fuel pump assy. .