ANOTHER p0430 question: V8 2uzfe, 200k miles timing belt explosion

[Streetfighter]

There are dozens of discussions out there on the code.
I know that I either need cats or just an o2 sensor.
I can even possibly get away with using a spacer to space it out with a fouler.

But i have a unique situation
My timing belt broke, causing it to misfire randomly (no engine damage).
I will make another thread with pictures on this...
shes back together and runs perfectly but it massively flooded through the headers during the troubleshooting process.

So, everything is great but the p0430 code.

So where should i start? Which o2 is this referring to? before the driverside cat or after?

any pointers from V8 owners?

inside info: 200k miles, cats and o2 never changed. Timing belt exploded and threw off timing everywhere. Changed everything back to new with plugs and EBAY coils.

She runs like a dream, getting 21-22 mpg on highway

THANKS IN ADVANCE

 

[Atlanta_man]

hope mine blows - would nice to get another 5+ mpg !

 

[MSRP.]

I'm chasing down mine as well, but here's one of the more comprehensive troubleshoots that I've found in my endless research. I don't have the link to the original thread, but I'm sure you can find it easily. Cut/paste:

P0430 Resolution

I also had the P0430 code on my 2006 4Runner SR5 V6 4WD with 142K miles. I verified the code with my code reader. I've been troubleshooting on the weekends over the past few months and finally figured it out.

In my case, the P0430 CIL code is triggered by the oxygen sensor downstream of the 1st CAT (driver's side on my particular vehicle). There's 4 CATs, but only the 1st two are monitored with O2 sensors (1st on driver's side and 1st on passenger side).

I did the following and the CIL always came back on:

Changed gas cap after reading some forums. Cheap & quick thing to do to rule it out. Didn't help.

Replaced O2 sensor downstream of driver's side CAT. About $85 for the part and installed myself. O2 sensors are 9 years old, so no harm in replacing. Didn't help.

Cleaned MAF sensor. Didn't help.

Ran fuel cleaner. Didn't help.

Replaced air filter. Didn't help.

Checked/cleaned throttle air body. Didn't help.

Checked for vacuum leaks in engine. None found.

Performed the WOT (Wide Open Throttle) test on highway (@ 55mph, press gas pedal to floor and accelerate to about 80+mph). No lack of performance, so I figured my CAT(s) were good and not clogged. Gas mileage has not suffered either which also helped me rule out a bad CAT(s).

I checked for air leaks in the exhaust system, specifically on the driver's side around the CAT. Using a spray bottle with soap, I honestly could not tell if the bubbles were air or just from steam / heat. I don't recommend this method to find leaks in your exhaust.

Finally, after watching youtube videos, I saw a method to easily locate air leaks in the exhaust. I hooked up my shop vac blower (pushing air - not sucking air) to my tailpipe, duct taped it well to the tailpipe, and turned the blower on. Using this method, I easily found 2 leaks in my exhaust. You could definitely hear it and then could feel the air pushing out (obviously make sure exhaust is not hot when you do this!).

One leak was at the driver's side CAT bolted flange location at the downstream side of CAT, immediately before the O2 sensor that I had replaced previously. I had a muffler shop replace the gasket and rusted bolts at that location. I then reset the CIL and haven't seen the light return in over a week.

Evidently, what had been happening is air/oxygen was getting sucked into that exhaust leak after the CAT. There's not supposed to be any Oxygen left after engine exhaust makes it through the CAT, so that was triggering the O2 sensor after the CAT; making it think the CAT wasn't performing properly..but it was.

I also want to point out that every time I reset the CIL, many times it would be triggered during rain, so I think the rain / humidity may have had helped contribute to triggering the O2 sensor at the leak / gasket.

This may not be the exact reason you are getting a P0430 code, but hopefully my experiences will help you narrow down some options to look into. Good luck!

 

[djkurious]

I'm chasing down mine as well, but here's one of the more comprehensive troubleshoots that I've found in my endless research. I don't have the link to the original thread, but I'm sure you can find it easily. Cut/paste:

P0430 Resolution

I also had the P0430 code on my 2006 4Runner SR5 V6 4WD with 142K miles. I verified the code with my code reader. I've been troubleshooting on the weekends over the past few months and finally figured it out.

In my case, the P0430 CIL code is triggered by the oxygen sensor downstream of the 1st CAT (driver's side on my particular vehicle). There's 4 CATs, but only the 1st two are monitored with O2 sensors (1st on driver's side and 1st on passenger side).

I did the following and the CIL always came back on:

Changed gas cap after reading some forums. Cheap & quick thing to do to rule it out. Didn't help.

Replaced O2 sensor downstream of driver's side CAT. About $85 for the part and installed myself. O2 sensors are 9 years old, so no harm in replacing. Didn't help.

Cleaned MAF sensor. Didn't help.

Ran fuel cleaner. Didn't help.

Replaced air filter. Didn't help.

Checked/cleaned throttle air body. Didn't help.

Checked for vacuum leaks in engine. None found.

Performed the WOT (Wide Open Throttle) test on highway (@ 55mph, press gas pedal to floor and accelerate to about 80+mph). No lack of performance, so I figured my CAT(s) were good and not clogged. Gas mileage has not suffered either which also helped me rule out a bad CAT(s).

I checked for air leaks in the exhaust system, specifically on the driver's side around the CAT. Using a spray bottle with soap, I honestly could not tell if the bubbles were air or just from steam / heat. I don't recommend this method to find leaks in your exhaust.

Finally, after watching youtube videos, I saw a method to easily locate air leaks in the exhaust. I hooked up my shop vac blower (pushing air - not sucking air) to my tailpipe, duct taped it well to the tailpipe, and turned the blower on. Using this method, I easily found 2 leaks in my exhaust. You could definitely hear it and then could feel the air pushing out (obviously make sure exhaust is not hot when you do this!).

One leak was at the driver's side CAT bolted flange location at the downstream side of CAT, immediately before the O2 sensor that I had replaced previously. I had a muffler shop replace the gasket and rusted bolts at that location. I then reset the CIL and haven't seen the light return in over a week.

Evidently, what had been happening is air/oxygen was getting sucked into that exhaust leak after the CAT. There's not supposed to be any Oxygen left after engine exhaust makes it through the CAT, so that was triggering the O2 sensor after the CAT; making it think the CAT wasn't performing properly..but it was.

I also want to point out that every time I reset the CIL, many times it would be triggered during rain, so I think the rain / humidity may have had helped contribute to triggering the O2 sensor at the leak / gasket.

This may not be the exact reason you are getting a P0430 code, but hopefully my experiences will help you narrow down some options to look into. Good luck!

^this^