My Ram flashed a trouble code this weekend. I checked it with my el-cheapo code scanner, and I got a 420. In my code book, it says that means catalyst efficiency below threshold bank one row one. Matbe a stupid question, but does this mean I have converter problems? And my plenum pan possibly leaking--again? I have fixed the pan before, maybe a year ago, and I use the felpro gasket. Any suggestions?

 

Anybody?

 

When you fixed your plenum did you order a kit from hughes or aps? If you didn't it is possible that it could be leaking again because the stock gasket isn't enough, those kits include a pretty thick piece of aluminum to prevent it from blowing out again. If you have access to an infared thermometer you can warm your truck up and measure the temps of the exhaust pipe before and after the cat and compare the readings. It should be hotter after the cat, if it isn't the cat is no good. Another way is to go drive around and get your truck good an warm then crawl underneath it and look at the cat, if it is glowing red from being so hot then you know it is no good.

 

does that glowing red thing really work, how long do u gotta be driving in order for it to be red, 30 min, 1 hour, 4 hours? lol

 

It isn't as surefire as getting a thermometer and doing it the right way, but if you don't have an infared thermometer it is a shadetree way to make it work. To answer you question though, yes it does work usually the cat has to be pretty bad but it will glow when it gets hot enough. Depending on how bad the cat is plugged it could take anywhere from 30 minutes to 2 hours. Years ago Chevy used to put protective covers over the cat on their trucks, but farmers would drive them through fields and grass would get packed between the covers and the cats, when the cat went bad in a dry grassy field they would have one hell of a grass fire.

 

lmao, i didn't know that

 

also, you can yank the front & rear o2 sensors and clean them with CRC electronic parts cleaner found at the auto parts store. spray the element holes liberally in all directions. let it dry then re-install. this stuff will leave no residue and will work on the o2 sensors. I had the same exact code on my wifes dakota and did this procedure and it cleared the code.

 

My truckthrew the same code but the cat is 6 months old. Could it be that the plenum is bad?

 

I personally hate cats.

 

What if you don't have a catalytic converter? The previous owner of my truck had it taken out. Sounds great, but it makes me worry that it will create more problems down the road.