what do plugged catalytic converters act like??

Discussion in 'Fox 5.0 Mustang Tech' started by BadAndy, Oct 8, 2006.

  1. Will pluged cats cause detonation???, I have tried everything else on my stock dailydriver [ 95 GT] , fuel filter fuel pump, timming is 9, ran lucas fuel inj cleaner threw it

  2. Have you cleaned the mass air flow meter yet?
  3. Whats your F.P. at? Is it running hot? How many miles on the motor?
  4. If your converters are plugged they will generally glow red hot & power will be signicantly down.

  5. Get a vacuum gauge. Measure it at idle, then rev to 2500, if you you get less vacuum at 2500, then that is a sign of clogged exaust. I have a backpressure gauge setup, but it isn't nessasary.

  6. yes
  7. thanks to all!!!! I dont think the cats are geting red hot and ill try the vac gauge trick!!
  8. does your exhaust stink like something horrible? That would indiacate bad cats too. Sometimes too if your driving and your smelling exhaust. If the cats are plugged your exhaust has to escape some how so it will come out where your exhaust bolts to your headers.

  9. did the vac test had 18 at idle and 20 at 2500rpm, maybe the cats are ok, the car is ok if i run mid grade gas so maybe i can deal with that
  10. Might be an overlook, but did you check timing? Is the spout connected? What exactly is it doing?
  11. If it smells like major crap, it's most likely the cats. Mine just burned out til they rattled, I chunked them for an X pipe and never looked back.
  12. To answer your initial question: I'd imagine it'd be like that time that you were at the all-you-can-eat Mexican buffet and that Chimi' got stuck on the way out. Then when it unlodged, people thought you were a mason. :D

    I'd do Jason's vac test but with a load on the motor (while on the highway, etc) if your car is driveable. Big difference between loaded and unloaded readings IMHO.

    Good luck.
  13. It will smell like rotten eggs. They can glow red too, but you might not see that if the shields are still around them. Take them babies off and put an O/R on anyways, the sound will be amazing.
  14. thats all good,

    I dont smell anything, the car pings under a load, but mid grade gas fixes it
  15. stock F.P --175.000 miles bone stock 5.0 95 GT
  16. It very well could be carbon buildup in the combusition chamber. Cleaning of the injectors might be a good idea. What is the fuel pressure under load?
  17. When your cats plug up your car bogs down hardcore... until you reach higher rpm. You still have a loss of pwr there, and the cats get very hot. Mine didn't get red hot, but you could see smoke coming form them, and they would vaporize any water that would hit them after only being run for a few minutes in the driveway.

    I pulled the h pipe and punched them out, much better. Have to buy new ones next year to pass smog :( But at least I have a off road h pipe that can poss visual inspection now ;)

  18. thats what im thinking, i did run lucas fuel inj cleaner threw it and many people say lucas inj cleaner works
  19. thanks to eveyone!!!! i think now its somthing other than cats, I just dont think i should have to bump up to mid grade gas on a stock 5.0
  20. Andy, the T4 processor (load-based 94-95 GT stick computer) is kinda famous for allowing the ping thing. Too much timing and too little fuel............

    You would not be the first 94-95 non Cobra guy who had to run premium to keep pinging at bay.

    Good luck.