Chasing codes on my 97 Tahoe

[61_FL_Apache]

Hey all, I have had the P0160 and P0161 for a while and finally got around to changing that sensor. Since then I know have P0430. I can clear it and its gone for a couple of days then it returns.

Any ideas?

Thanks for your help!

[87Skier]

A code P0430 may mean that one or more of the following has happened:

• The catalytic converter is no longer functioning properly
• An oxygen sensor is not reading (functioning) properly
• There is an exhaust leak

I would start by making sure you don't have any exhaust leaks. Then, if you have a good quality scanner, you can check the O2 sensors to see if they are reading correctly.

Beyond that you will probably need to look at replacing parts.

[Killer Bee]

Originally Posted by 61_FL_Apache

Hey all, I have had the P0160 and P0161 for a while and finally got around to changing that sensor. Since then I know have P0430. I can clear it and its gone for a couple of days then it returns.

Any ideas?

Thanks for your help!

in bold could very well lead to a damaged cat, not uncommon.. but wise to check the basics mentioned above..

while OBDII is not my primary background, I supervise a few techs that encounter this frequently..

without O2's functioning properly, the ecm relies on base data [usually on the rich side] that may result in extra work for the cat..

once sensor is replaced and system goes into closed loop [feedback], voila, it can now tell you the system is not working efficiently..

this is commonly a now failed cat, but can also be another faulty O2 sensor, still working possibly but reporting bad data [lazy usually]

let us know what engine model, exhaust configuration, number of O2s, cats, etc. and hopefully a well versed OBDII guy can speed this up for you..

also let us know if you have a live data scanner and which one, there are tests that you can run that may lead you to the solution..

there are also LOTS of youtoobs demonstrating your very symptoms, maybe one of them can get you rolling faster as well..

please keep us posted and good luck!

[61_FL_Apache]

I have a mechanic I call on from time to time and he probably has the scanner needed for more detailed info. I just have a code reader so it doesnt tell you much. The truck runs fine, im getting tired of the CEL. Im surprised the bulb has not burned out yet.

Thanks for the feedback!

[speedygonzales]

The previous codes 160 & 161 were after cat O2s. The 430 is cat efficiency.

The rear (aftercat) O2s are only used to check on the health of the cat. They do NOT have anything to do with control of the engine. That is what the front O2s are for.

You need to understand how and when the engine checks on the health of the cats. And thus reading the rear O2s. They are not used constantly.

One thing I can tell you is our vehicles do not like aftermarket sensors. I could never get Bosch to work. And it took days for the code to appear.

Keep that in mind.