can failing cat cause misfires?

patredbruin · Post by **patredbruin** » 21 Jun 2010, 19:27

can a failing cat converter cause misfires and foul plugs?

Post by **Ozark Lee** » 21 Jun 2010, 20:40

It can but I would look elsewhere first.

What codes are you throwing and under what conditions?

...Lee

850tech · Post by **850tech** » 21 Jun 2010, 20:56

The misfires and fouled plugs are probably the cause of your failed or failing cat, you need to get to the root of those problems first. Even if your cat is clogged and causing a significant stumble and lack power, it would only have got that way from excessive unburnt fuel entering the exhaust and collecting in the cat, i.e. misfires.

patredbruin · Post by **patredbruin** » 27 Jun 2010, 11:31

misfiring on all cyl codes P0301, 02, 03, 04, 05 i'm wondering if i'm getting unmetered air about the only thing i have'nt done is pull off and inspect the hose from the maf to the turbo, what is that sensor near the bottom of the hose?

Post by **Ozark Lee** » 27 Jun 2010, 12:41

If it is what I think you are describing it isn't actually a sensor, it is a heater. Volvo calls it a PTC valve. Make sure it isn't plugged up with carbon and you can be aggressive with it.

...Lee

patredbruin · Post by **patredbruin** » 27 Jun 2010, 12:54

thanks lee wasn't sure if i could manhandle it that will be the next project. i've replaced plugs cap rotor wires maf crank sensor cam sensor tps idle control valve socked up hose from intercooler to intake(thought i had it ran good 2 days then cyl misfire codes again)if that does'nt do it have to shell out the $$$$ at the dealer. 1995 850 turbo wagon 177905miles