Happster
Member
- Joined
- January 19, 2009
- Messages
- 39
- Reaction score
- 3
- City, State
- Dunstable, MA
- Year, Model & Trim Level
- 2017 Explorer XLT 3.5L V6
Getting a persistent P0430 Code, the dreaded bank 2 cat insufficiency code in my wife's Exploder. The history:
Unbeknownst to me, she was getting a misfire code in 5 or 6 and drove it like that for about 15,000 miles. I took the intake off to get to the injectors to replace them only to discover that the intake ports in the lower intake plenum for cylinders 5 and 6 were seriously gummed up with white sludge. I thought maybe the misfire/lack of fire was allowing condensation to take over. I cleaned out the ports, replaced the injectors, plugs and wires and she ran like a top and has ever since. Fuel trims are perfect.
After about 10k she popped a P0430 Code bank 2 cat insufficiency. Still running great, no other codes. I figured she gummed up the cat by driving it with a misfire, since cylinders 5 and 6 are obviously on bank 2. At first, I replaced both censors on bank 2 and tried boiling the cat in citric and some other form of acid based upon some blogs online. That worked for about 5k miles, and the code came back. I then replaced the cat. I did not get OEM, but I also did not go for cheapest...middle of the road. Code came back fairly quickly after replacing the cat and it has been on since (about 15k miles).
I took a laser temp gun and recorded about 500 degrees F exiting bank 2 (pre-cat) and about 600-650 post cat with the engine at about 2500 RPM. Bank 1 was similar. Both cats seem to be doing their job. Live data on my OBDII scan tool showed that both cats were almost identical in temp at 2500 RPMs- they both were 1300F. The upstream sensors in both banks were quickly vacillating between .1 and .9V and the downstream at a steady .7V, which I understand to indicate normal function. Yet the Code remains. One interesting thing that may be relevant is that even when I erase the code, it stays in the "permanent" code section of the scanner. Fuel trims are perfect. No other codes after driving 15k miles with this issue.
Anyway, I'm at wits end. I'm thinking maybe there is a leak in the intake? A crack, or it needs new studs and nuts? But wouldn't that trip a lean code? And again, the EGTs coming out of both banks are about the same. I saw no visible cracks in the intake and put a new gasket in when I replaced the injectors. I've also heard that sometimes you need to reprogram the ECU when putting in new components?
Going to try a defeat extender on the downstream O2 sensor on bank 2, since it is running and behaving normally by all measures that I can gather. But I'd like to get it right. Thoughts appreciated on what else it can be, or what else I can do to troubleshoot.
Thanks.
Mike
Unbeknownst to me, she was getting a misfire code in 5 or 6 and drove it like that for about 15,000 miles. I took the intake off to get to the injectors to replace them only to discover that the intake ports in the lower intake plenum for cylinders 5 and 6 were seriously gummed up with white sludge. I thought maybe the misfire/lack of fire was allowing condensation to take over. I cleaned out the ports, replaced the injectors, plugs and wires and she ran like a top and has ever since. Fuel trims are perfect.
After about 10k she popped a P0430 Code bank 2 cat insufficiency. Still running great, no other codes. I figured she gummed up the cat by driving it with a misfire, since cylinders 5 and 6 are obviously on bank 2. At first, I replaced both censors on bank 2 and tried boiling the cat in citric and some other form of acid based upon some blogs online. That worked for about 5k miles, and the code came back. I then replaced the cat. I did not get OEM, but I also did not go for cheapest...middle of the road. Code came back fairly quickly after replacing the cat and it has been on since (about 15k miles).
I took a laser temp gun and recorded about 500 degrees F exiting bank 2 (pre-cat) and about 600-650 post cat with the engine at about 2500 RPM. Bank 1 was similar. Both cats seem to be doing their job. Live data on my OBDII scan tool showed that both cats were almost identical in temp at 2500 RPMs- they both were 1300F. The upstream sensors in both banks were quickly vacillating between .1 and .9V and the downstream at a steady .7V, which I understand to indicate normal function. Yet the Code remains. One interesting thing that may be relevant is that even when I erase the code, it stays in the "permanent" code section of the scanner. Fuel trims are perfect. No other codes after driving 15k miles with this issue.
Anyway, I'm at wits end. I'm thinking maybe there is a leak in the intake? A crack, or it needs new studs and nuts? But wouldn't that trip a lean code? And again, the EGTs coming out of both banks are about the same. I saw no visible cracks in the intake and put a new gasket in when I replaced the injectors. I've also heard that sometimes you need to reprogram the ECU when putting in new components?
Going to try a defeat extender on the downstream O2 sensor on bank 2, since it is running and behaving normally by all measures that I can gather. But I'd like to get it right. Thoughts appreciated on what else it can be, or what else I can do to troubleshoot.
Thanks.
Mike
