I hope one of you has had this problem and can help.

For the past six years I have had to replace the cat or o2 sensors to pass emissions test.
I have a 2003 high sport SS with the 3.8L

twice i did the cat and both times it lasted about a month.

the rest of the times, i did both o2 sensors but this only lasts a few days.

So, I have a feeling that something is causing this BS to happen. I am sick and tired of spending hundreds of dollars every year to pass emissions. and have started to consider unloading the car due to this issue.

Here's some other facts that may help..... I bought the car 6 years ago with 42k on it. about six months later, the power dropped and the mechanic said it was the cat. instead or replacing it, i had it hollowed out and reinstalled. the following year i put on a u bend delete cat and removed the resonator and passed emissions but a couple months later the catalyst code came on. so i waited till inspection was due and put another u bend delete cat on. same thing, a month later the catalyst code came on again.

Since then I discovered it was cheaper to change both o2 sensors to pass emissions. even though this repair only lasts a few days it has allowed me enough time to pass. This costs me about 200-300 versus the cat wich costs 400-500.

What the hell is going on here? this car is getting on my nerves.


ALSO, is there anyway to disable my day time running lights?

 

I'm curious...

How many miles do you have on it now?

Do you have to keep topping off the radiator with Anti-Freeze?

Is there a milky substance in the radiator, or overflow?

When you pull of the oil filler cap..do you also see a milk shake color in and around the edges and valve cover?

When you replace the O2 sensor... Does it look corroted? burnt?

 

What code is coming up to cause you to believe your .Cat and 02 sensors are bad?
If it is P0420, it's not that your cat is bad, it's the factthat your cat is aftermarket. I ccan't explain the details of how it works but the freer flowing exhaust is not read as easily by the 02s.
A couple of the Members here have the ability to remove the P0420 code So it never shows up and you pass inspection.
Search for PMC Service post and you can get it fixed inexpensively. If That's the code! These Members can do other things to the programming of the PCM. But you have to contact them to find out what.
Hope this helps!

 

right now im getting codes p0141 and p0135 BUT i was getting the p0420 code before. I cleared the codes a few days ago due to the maf change so the p0420 may not have hit yet, but it will. lol

shes got 116k miles on it now. and no head gasket problems. last year i had to do the intake gasket and tubing elbows issue we all have so fluids are all pristine. Never need to add coolant. Inside of motor is spotless. I change oil every 3k miles. the motor itself is running very strong. you would think the car was brand new really. it is an amazing engine, and i swear by it. maybe i will just go back to a stock cat. i think here in NY they just passed a new law requiring only original factory cats on all cars anyway. really the only issue it has besides this is the power steering makes a whinning noise but i heard that its a common problem on these cars.

I was hoping to get the zzp supercharger kit for it and add a CAI intake along with headers and a nice exhaust system but now im not so sure.

 

The county I live in requires emissions testing upon inspection. my brother 2 countys over does not. What this means is more headaches for me, but I keep telling myself its going to run optimal, and paying the money to fix the codes pans out vs. skipping over emissions and paying the bigger bill in the end, not to mention bad MPG.

I'm going to try and fix my p0141 code this weekend with a downstream AC Delco sensor. I got Bank 1, sensor 2 code, so I will post hopefully a successful fix, but I will also look over the wiring as well, and test.

I'm also dealing with a p0463(changed fuel pump already) and p0440 (assuming gas cap)...

 

I have the feeling you have an after market cat. A common problem with aftermarket cats is that they only work for so long and then will throw codes. So just get the code tuned out. There is almost no way you are fowling a cat every few months. If you were you would have some SERIOUS evap codes and terrible gas consumption. Your cat is still doing its job and you would probably even pass a tail pipe sniffer insepction. But beacuse aftermarket cats are made with cheaper materials they dont always fit in the fine tuned specs of the O2 sensors that were designed for an oem cat.

 

I suggest you both do a running diagnostic. There are other things in the fuel system that can cause an 02 sensor code. I had the P0141 code. It turned out to be part of the MAS problem. The MAS can cause codes downstream from it without popping a MAS code.
Look up The_Maniac, he can delete the P0420 code from the PCM and as I understand it, deleting that code does not cause problems with emissions inspection. I'm in the same boat. My inspection is due in April and I have a Magnaflow Cat.

 

JC what is the "MAS"?

 

Mass Airflow Sensor
You gotta excuse me. I'm an Old School Wrench Head. MAS is what We called it 25 yrs ago.

 

lol ok, all good bud!