Photo and video: Dreaded p0430 & p0440 code

[Unabashedpraise]

History: bought 1999 k1500 5.7 a few years ago that had an intake leak. I replaced old injectors with new spider model but struggled to get the intake to seal. Had to redo it twice and ended up using k seal. Have not had a problem with coolant loss since then. The computer had given a p0430 and p0440 before the repair. It still has the code. I used torque pro the other day to check my o2 sensors. This is what it showed.

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Your thoughts? I assume the massive amounts of coolant running though the exhaust could have ruined the cats and sensors, not to mention the weak injectors going for who knows how long.

I'm trying to figure out what to do about this. I have been thinking of new exhaust and possibly a tune for better performance. In Missouri they do not test for emissions.

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[SAATR]

Bank 2 sensor 2 is dead. You can either buy a new sensor and replace it, or swap the known good Bank 1 sensor 2 in its place to verify that you don't have a wiring fault. Either way, you're pulling that sensor. P0440 is evaporative emissions and has nothing to do with the exhaust system.

 

[Unabashedpraise]

Bank 2 sensor 2 is dead. You can either buy a new sensor and replace it, or swap the known good Bank 1 sensor 2 in its place to verify that you don't have a wiring fault. Either way, you're pulling that sensor. P0440 is evaporative emissions and has nothing to do with the exhaust system.

Would a bad cat have anything to do with it?

 

[SAATR]

Would a bad cat have anything to do with it?

No. It's not tracking any fuel/air ratio changes at all, so it's either not installed in the exhaust stream or it is non functional. Again, the zero dollar solution is to swap downstream sensors and see if the dead signal follows the sensor. If it does, you have a bad sensor. If it doesn't, you have a wiring issue. A bad cat would still read on the downstream.

 

[stutaeng]

I didn't understand what the graphs were showing on the video, but agree that B2S2 looks dead, but I had one showing pegged when in reality it was correct and one bank was lean. However, my code was lean code and fuel trims helped me rule out bad O2 sensors. By then I had already replaced all 4.

I believe you can spray some carb cleaner into intake and see if you see any change in voltage. If it's still pegged then it's bad. Or you can swap them.

I didn't know these trucks got EVAP codes. I was messing with a LQ4 engine on one of my trucks and found a video on how to test a purge solenoid. Just for fun, I tested the solenoid on my 5.7 and it was not opening with 12V test voltage, but truck never threw a code, maybe it wasn't supposed, don't know.

Anyhow, here's the video:
https://www.google.com/url?sa=t&sou...=nfIsYtiH94M&usg=AOvVaw3XpH2YyPweIDhJqD6KaTBB

 

[Unabashedpraise]

No. It's not tracking any fuel/air ratio changes at all, so it's either not installed in the exhaust stream or it is non functional. Again, the zero dollar solution is to swap downstream sensors and see if the dead signal follows the sensor. If it does, you have a bad sensor. If it doesn't, you have a wiring issue. A bad cat would still read on the downstream.

I visually checked the wiring and made sure the sensor was in fact installed. No obviousiobvious there. Was going to trade the downstream sensors, but my goodness those things are stuck tight. At this point I'm afraid I'll break something trying to get them off. I'm contemplating buying a sensor and have it installed along with a new muffler.

I ended up changing my front wheel hubs instead.

 

[HotWheelsBurban]

The rear O2 sensors on my 99 Burb 5.7 have a 7/8" hex on them. The wrench I use is big enough for some leverage, and I've been able to get them loose with it. The pipes have to be heated up a bit to expand everything and make it easier to remove. 10 minutes or so should do the trick. Have the truck in the air some so you can get under it without burning yourself on the pipes. They don't need to be super hot, but the sensor won't come out cold unless you're luckier than I've been. IIRC the GM procedure is to heat the pipe up by running the vehicle for 10 to 15 minutes.
I've had to replace both the rear bank sensors on my truck, apparently on some vortecs the rears don't last more than a year or two. Thankfully those are the easier ones to change. You have to be very careful about using penetrating oil on these because it is flammable and you don't need that on the exhaust pipes! Try the warm pipes, that should help.
When you do get it out, be sure you use the anti seize compound on the replacement sensor. The ones I bought came with some on them; if you put any on, just don't get any on the end of the sensor that goes into the exhaust pipe. Hope this helps

 

[SAATR]

I visually checked the wiring and made sure the sensor was in fact installed. No obviousiobvious there. Was going to trade the downstream sensors, but my goodness those things are stuck tight. At this point I'm afraid I'll break something trying to get them off. I'm contemplating buying a sensor and have it installed along with a new muffler.

I ended up changing my front wheel hubs instead.

For what they cost, I'd buy a new one and disregard the swapping procedure. As mentioned above, having the exhaust warm can help greatly. I have an extra deep 7/8 socket that I use with either a breaker bar or a 1/2" impact once I cut the wires off the old sensor. Haven't failed to remove one that way yet. Penetrating oil can work, just don't overdo it. As far downstream and the rear 02 sensors are, it will evaporate the lighter hydrocarbons and the rest will just smoke until it is gone. Spraying with oil, followed by idling for several minutes, followed by another spraying can help work the lubricant into the threads.

Also, a couple of sharp blows with a hammer on the socket while the socket is on the sensor can help motivate things. If none of this sounds feasible or desirable, then just have it done by somebody.

 

[alpinecrick]

Ditto on warm exhaust.