P0430 code

**98TransAmWs-6** · 10-03-2010, 12:40 PM

The p0430 error code popped up after I got my coolant sensor fixed and exhaust adjusted at a shop. What would cause this? The exhaust system is obx lts and y-pipe ,high flow cats, and slp loudmouth. My exhaust is only 1 month old. So how could my cats be clogged? At higher rpms it back fires or sounds like it but I don't see any smoke. Could an exhaust leak cause this? Any with what could cause this would be greatly appreciated.

**02transamce** · 10-03-2010, 02:02 PM

p0430 is a catalyst code, could be your high flow cats are flowing more than what the sensor wants to see causing the code.

**98TransAmWs-6** · 10-03-2010, 02:15 PM

Originally Posted by 02transamce

p0430 is a catalyst code, could be your high flow cats are flowing more than what the sensor wants to see causing the code.

But they've been on for more than a month so why would the code come up only after I got it back from the shop it was at on friday? Is it possible that they didn't hook something back up when adjusting my exhaust that would cause this code? If it is that they are flowing more than the sensor wants how could I fix this?

**02transamce** · 10-03-2010, 03:31 PM

It is possible that one of the o2 sensors could not be plugged up or damaged.check to make sure the connector is plugged up good and tight and none of the wires are damaged.
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**98TransAmWs-6** · 10-03-2010, 04:23 PM

Originally Posted by 02transamce

It is possible that one of the o2 sensors could not be plugged up or damaged.check to make sure the connector is plugged up good and tight and none of the wires are damaged.
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Okay I'll check that out. The O2 sensors shouldn't be bad though, I have 4 new ones that are just over a month old.

**02transamce** · 10-03-2010, 04:29 PM

Yeah,but who knows the wires can get damaged pretty easy.
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**98TransAmWs-6** · 10-03-2010, 04:33 PM

Originally Posted by 02transamce

Yeah,but who knows the wires can get damaged pretty easy.
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By wires do you mean the ones in the actual O2 sensor or what the O2 sensor plugs into (the wire harness)?

**02transamce** · 10-03-2010, 04:52 PM

The ones that go from the connector the the sensor body
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**98TransAmWs-6** · 10-03-2010, 04:57 PM

Ah ok well I'll be checking that in the morning. If it is not that or an exhaust leak is it at all likely that it is my cat? If it is then I am thinking the shop I took it to is going to have to buy me a new one since it happened only after I got it back from them.

**Cutlass** · 10-03-2010, 05:21 PM

Generally that code only means one thing, the cat is no longer functioning correctly. Doesn't necessarily mean its clogged, just means it not converting exhaust emissions as effectively as the computer wants it to. Therefore its unlikely the exhaust shop ruined your converter. Unless they put a big dent in it.
So if there aren't any exhaust leaks (especially near the post cat O2 sensor), then most likely the cat has failed. What brand cat is it?

**98TransAmWs-6** · 10-03-2010, 05:38 PM

Originally Posted by Cutlass

Generally that code only means one thing, the cat is no longer functioning correctly. Doesn't necessarily mean its clogged, just means it not converting exhaust emissions as effectively as the computer wants it to. Therefore its unlikely the exhaust shop ruined your converter. Unless they put a big dent in it.
So if there aren't any exhaust leaks (especially near the post cat O2 sensor), then most likely the cat has failed. What brand cat is it?

They are brand new though. Why would one fail and not the other? They are OBX.

**Cutlass** · 10-03-2010, 05:47 PM

doesn't really matter if they are brand new. It could be defective or its possibly just cheap crap that doesn't really last long.
The reason they don't fail at the same time is the same reason why 2 brand new light bulbs in a light fixture don't fail at the same time...manufacturing variance

**98TransAmWs-6** · 10-03-2010, 06:12 PM

Originally Posted by Cutlass

doesn't really matter if they are brand new. It could be defective or its possibly just cheap crap that doesn't really last long.
The reason they don't fail at the same time is the same reason why 2 brand new light bulbs in a light fixture don't fail at the same time...manufacturing variance

Okay so should I have a shop check it out or replace it myself? Also by looking at it how do you tell if it's bad? Why would it fail? I would like to find the reason so it doesn't happen again or at least for a long time. Sry if I sound stupid I am just not sure what to do.

**Cutlass** · 10-03-2010, 06:21 PM

Engine running rich or misfiring can cause excessive gasoline in the converter. That kills converters fast.
Generally you can't just look at a converter and tell its bad. You either just go by what the trouble code says or have the exhaust emissions measured for pollution at the tailpipe.

**Cutlass** · 10-03-2010, 06:21 PM

It wouldn't be a bad idea to just clear the code out and see if it returns.

**98TransAmWs-6** · 10-03-2010, 06:25 PM

Originally Posted by Cutlass

It wouldn't be a bad idea to just clear the code out and see if it returns.

My car backfires at higher rpms, if there wasn't really a problem wouldn't it not backfire? The backfiring is caused by this code right? I guess I'll look for leaks and then clear the code and see what happens. Also I did have a misfire for a little while but I did not drive it much so maybe that damaged it.

**Marc 85Z28** · 10-04-2010, 07:56 AM

ALL aftermarket converters are cheap crap, no matter what you pay for them. They use far less precious metals to reduce cost as compared to the OEMs. IMO and extensive experience in the industry, aftermarket converters have no place on an OBD-II vehicle.

Your best bet is to remove the catalyst monitors (rear O2s) and have them tuned out.

**98TransAmWs-6** · 10-04-2010, 11:05 AM

Originally Posted by Marc 85Z28

ALL aftermarket converters are cheap crap, no matter what you pay for them. They use far less precious metals to reduce cost as compared to the OEMs. IMO and extensive experience in the industry, aftermarket converters have no place on an OBD-II vehicle.

Your best bet is to remove the catalyst monitors (rear O2s) and have them tuned out.

Won't I still have the backfire if my converter is bad though?

**Marc 85Z28** · 10-04-2010, 11:45 AM

Originally Posted by 98TransAmWs-6

Won't I still have the backfire if my converter is bad though?

Are you sure you're using the term backfiring correctly? A backfire is through the intake and is very loud, like a shotgun blast. Or are you getting afterfire, a popping noise in the exhaust system?

The only way a catalytic converter could affect engine operation is if it was clogged. The PCM will not set an inefficiency DTC on a clogged converter, only one that is inefficient. Flow restriction is irrelevant.

**98TransAmWs-6** · 10-04-2010, 12:49 PM

Originally Posted by Marc 85Z28

Are you sure you're using the term backfiring correctly? A backfire is through the intake and is very loud, like a shotgun blast. Or are you getting afterfire, a popping noise in the exhaust system?

The only way a catalytic converter could affect engine operation is if it was clogged. The PCM will not set an inefficiency DTC on a clogged converter, only one that is inefficient. Flow restriction is irrelevant.

I guess then technically it is an afterfire but like I mentioned before it is at higher rpms.