Residue after catalytic converter
Thread Starter
Moderator
Joined: 01-23-2009
Posts: 26,539
From: Fredericksburg,VA
The saga continues!
Installed New injectors. tested compression because there seemed to be a lot of carbon in the holes, #4 was 20 psi higher than the others.
It started passing the catalyst monitor twice then failing. I put the old cat back on, so far it has passed the catalyst monitor 4 times.
I'm now thinking it was a bad injector all along and the replacement cat has leaking welds. Now trying to noodle a leak test apparatus for the waste of $190 cat from Canada, can't afford shipping it back.
But of course, since I'm mentioning it in public the CEL will be back soon.
Installed New injectors. tested compression because there seemed to be a lot of carbon in the holes, #4 was 20 psi higher than the others.
It started passing the catalyst monitor twice then failing. I put the old cat back on, so far it has passed the catalyst monitor 4 times.
I'm now thinking it was a bad injector all along and the replacement cat has leaking welds. Now trying to noodle a leak test apparatus for the waste of $190 cat from Canada, can't afford shipping it back.
But of course, since I'm mentioning it in public the CEL will be back soon.
Member
Joined: 02-20-2014
Posts: 36
From: na
DonBrew, are the compression readings in the other cylinders within about a 10% range from highest to lowest readings? If so then I would see about removing a carbon buildup in cyl 4. Can you bench test the injector from cyl 4 to see if it was leaking? You already know how important it is to have no leaks in the exhaust system at the cats or before them.
Thread Starter
Moderator
Joined: 01-23-2009
Posts: 26,539
From: Fredericksburg,VA
In another post I answered all of that, forgot where I was.
#1 180, #2 180, #3 175, #4 200. #3 may be operator error.
It was cheaper to just replace the injectors @ $22 per than to have them tested. P0420 is gone for now. Seems to have gained 1-2 MPG. Idle still rough, like any 4 cylinder. I had noticed a flutter at around 1500 RPM in the garage, not on the road, which was another pointer to injectors.
SeaFoam is currently being used aggressively.
#1 180, #2 180, #3 175, #4 200. #3 may be operator error.
It was cheaper to just replace the injectors @ $22 per than to have them tested. P0420 is gone for now. Seems to have gained 1-2 MPG. Idle still rough, like any 4 cylinder. I had noticed a flutter at around 1500 RPM in the garage, not on the road, which was another pointer to injectors.
SeaFoam is currently being used aggressively.
Senior Member
Joined: 10-13-2013
Posts: 101
From: Blaine WA
I even tried an internet search.
I got a P0420 the other day, cleared it. Popped back a few thousand later. I was hoping that it was my flex pipe, since I have a new one in the garage.
I pulled the catalytic converter off. The 2008-2011 LTs actually have 2 on the one pipe. The flex pipe is good.
My observation: The inside of the pipe at the header end is a bit sooty (dry). But, the inside of the pipe after the second cat is oily and has small white particles in it.
So, I am writing off the cat I guess. The question is: What is the oily stuff? Is that the cause of failure? What's the cause of the oily stuff? I do not want to destroy a new cat.
I got a P0420 the other day, cleared it. Popped back a few thousand later. I was hoping that it was my flex pipe, since I have a new one in the garage.
I pulled the catalytic converter off. The 2008-2011 LTs actually have 2 on the one pipe. The flex pipe is good.
My observation: The inside of the pipe at the header end is a bit sooty (dry). But, the inside of the pipe after the second cat is oily and has small white particles in it.
So, I am writing off the cat I guess. The question is: What is the oily stuff? Is that the cause of failure? What's the cause of the oily stuff? I do not want to destroy a new cat.
Thread Starter
Moderator
Joined: 01-23-2009
Posts: 26,539
From: Fredericksburg,VA
Depends on your state inspection, some do a visual.
Why bother cutting the second one out at all? It does have a function in back pressure just like the resonator does.
A CARB cat to fit the pipe runs less than $200, then add labor. Get new O2 sensors, or you'll be sorry. So, about $380 in parts.
BTW, I found out that it is illegal for any shop to charge to replace a cat if it is under warranty. In other words: if it is still under warranty you MUST exercise the warrantee.
Why bother cutting the second one out at all? It does have a function in back pressure just like the resonator does.
A CARB cat to fit the pipe runs less than $200, then add labor. Get new O2 sensors, or you'll be sorry. So, about $380 in parts.
BTW, I found out that it is illegal for any shop to charge to replace a cat if it is under warranty. In other words: if it is still under warranty you MUST exercise the warrantee.
Senior Member
Joined: 10-13-2013
Posts: 101
From: Blaine WA
almost. No, that's for the forward cat that's bad. good suggestion re: O2
I know there is a lot of bad mechanics out there, but in this small town I know who's good and who ain't. I've been involved in the auto fraternity around here since I started driving in 1962, so I know who to trust.
There are still gearheads around that I worked with in the '60's (the good, the bad, the ugly)
My mech will make good on anything that goes wrong.
I know there is a lot of bad mechanics out there, but in this small town I know who's good and who ain't. I've been involved in the auto fraternity around here since I started driving in 1962, so I know who to trust.
There are still gearheads around that I worked with in the '60's (the good, the bad, the ugly)
My mech will make good on anything that goes wrong.