I am trying to change the catalytic converter and I can;'t get the nuts loose. The two at the rear came lose with a cheater bar. I now have broken out the pneumatic impact wrench and the others still want come lose. Before I try to come up with a long cheater bar, does anyone have nay ideas.

Hopefully thanks
In advance

 

Try some PB Blaster and give it an hour to work itself in.

 

X2. if that fails, about the only other option is to heat them up...



:chug:

 

If you get a longer "cheater bar" they will probably break off. Try penetrating oil as stated above (PB blaster is one of the best). After that you will need a torch.

 

Take it out, hollow the cat, then put it back it. Instant performance upgrade! Just not so smog legal.

 

I believe most modern cars will also throw a check engine light if you 'gut the cat'.

 

Not to mention running like crap cuz the ECM can't make the fuel/air ratio right.