A/F Problem.. Please help!
Thread Starter
Teching In
Joined: Aug 2002
Posts: 45
Likes: 0
From: Dallas, TX
A/F Problem.. Please help! A little history first ...
Soon after I got my Hooker LT headers installed my drivers side cat burns out. I replace the cat, get the exhuast all welded up and then notice a ticking sound coming from the passenger side engine bay.
So I buy an AutoTap and MAFT and spend the next few months dialing in my LTFT to 0. MAFT base is set to 10% rich and WOT set to 2% lean. Finally I took it to the Dyno and pulled about 12.4 to 12.7 A/F @ WOT. Funny thing is it starts at 14 to 15 @ 2600 RPMs before leveling out at about 2900 RPMs.
I try to get rid of the ticking sound by replacing the plugs, A.I.R valves and doing the restrictor mod to no avail.
Skip forward a few more months. My driver side cat burns out again. I hear it rattleling for a few days and then it goes quite. I think by this time the cat is gutted. The SES light comes on a week later. Having sold my Autotap I instead take to Autozone. They pull code 1133 which is the bank 1 O2 detecting a lean condition. I thought cats burnt out from a rich condition?
At this point I am totally confused and ready to take it to the dealership and throw a bunch of $$ at it.
Any thoughts?
Soon after I got my Hooker LT headers installed my drivers side cat burns out. I replace the cat, get the exhuast all welded up and then notice a ticking sound coming from the passenger side engine bay.
So I buy an AutoTap and MAFT and spend the next few months dialing in my LTFT to 0. MAFT base is set to 10% rich and WOT set to 2% lean. Finally I took it to the Dyno and pulled about 12.4 to 12.7 A/F @ WOT. Funny thing is it starts at 14 to 15 @ 2600 RPMs before leveling out at about 2900 RPMs.
I try to get rid of the ticking sound by replacing the plugs, A.I.R valves and doing the restrictor mod to no avail.
Skip forward a few more months. My driver side cat burns out again. I hear it rattleling for a few days and then it goes quite. I think by this time the cat is gutted. The SES light comes on a week later. Having sold my Autotap I instead take to Autozone. They pull code 1133 which is the bank 1 O2 detecting a lean condition. I thought cats burnt out from a rich condition?
At this point I am totally confused and ready to take it to the dealership and throw a bunch of $$ at it.
Any thoughts?
Thread Starter
Teching In
Joined: Aug 2002
Posts: 45
Likes: 0
From: Dallas, TX
No, I have O2 sims behind the cats.
The SES light went off today. I am hesitant to take to the dealer. I am sure that whatever they find wont be covered under warrenty because of the mods.
I am going to take it to an exhaust shop and check it for leaks. I don't have any black smear marks around the headers or at any of the welded joins so I am doubtful. I am going to try replacing my plugs, wires and O2 sensors.
I dont want to replace the cats again until I know what is killing them. If I was running rich I could understand it but my last Autotap and dyno from several months ago indicated that I was all dialed in.
Other than these problems the car runs fine.
The SES light went off today. I am hesitant to take to the dealer. I am sure that whatever they find wont be covered under warrenty because of the mods.
I am going to take it to an exhaust shop and check it for leaks. I don't have any black smear marks around the headers or at any of the welded joins so I am doubtful. I am going to try replacing my plugs, wires and O2 sensors.
I dont want to replace the cats again until I know what is killing them. If I was running rich I could understand it but my last Autotap and dyno from several months ago indicated that I was all dialed in.
Other than these problems the car runs fine.
