Remember a few weeks back when the truck was running lean and I got that Catalyst Low Efficiency code and I fattened it up a bit wth edit to try an fix it? Well after I fattened it up I found the true problem and I was getting a lot of unmetered air. After fixing that I rode around a few days with the fat tune and got a lterm excessively rich code before I fixed it. Now the fuel is right according to autotap but the truck is running like crap. The best I could do at the track with the new converter was a 14.82@90 last week which is terriable. It feels good on low end but dies at the top of second and in third. I have been racking my brain tring to figure out what could be wrong with my truck. Well, low and behold, I got another SES light today and guess what it was... Catalyst System Low Efficency! It came on just as I was getting to work so I put Autotap on it in the parking lot and the lterms looked good, so.... anyone else think it is time for me to kill the cats and see if that is my problem?

 

delete the cats and see how you like it then

 

If you want some stock cats I have some for sale Pm me.

 

I think I am just going to take them off since we have no emissions testing here in Mississippi. I just wanted to see if you guys though that my cats were going bad and if that was possibly my problem?
BTW.. Which cylinder bank is Bank1? My codes are p0420 and h0420 which indicate the cat on bank1.

 

Hey Kenneth,I think it's your cat's also.Cut them off and get you a good y-pipe made.It should help out.

 

I am going to try and get that done today but I may not make it home in time from school.
With the true-duals I wont have a y-pipe but I do plan on haveing new pipe put in from the collectors to the x.

 

Ken, what are you going to do about the o2 sensors?

 

Yeah,I forgot you had true dual's again

 

Hey, My dad's truck has the same code set for the passenger side rear O2. I was thinking it was a dead cat also.

He's got 150K+++ and some miles on his truck. Did your gas mileage take a nose dive? His dropped like 2mpg just recently, a little before the code set.

Anybody have a spare set of low mileage 6.0L cats laying around they want to get rid of?

John

 

Jeff... I have edit and will just turn them off.

John... My gas mileage took a dive a long time ago. But I really haven't noticed it being any worse that before. Actually with this latest tune, I got the best I have gotten in a long time. 18.1mpg. I was pretty shocked. Since this last tune I also havent gotten anymore codes, but my ltrims are also nearly perfect too. It still feels like a turd though.