Hey thanks guys for your time and help. I have had my SES light on for a couple thousand miles so far. I just got back from the dealership today and they diagnosed my SES light and pulled a P0420. They told me I need a new Cat (bank 1) and bank 1 O2 sensors 1 and 2. They quoted me at $1920!!! I live in MA but it's a Cali spec. I'm definitely not going with their price... At this point I just have no idea what to do.

I also noticed my car runs kinda crappy. I have been doing research and can't seem to find a great explanation on what exactly to do with my car. It feels as if it bucks while i'm trying to accelerate. As I am slowing down sometimes at very low speeds, normally slowing from 15 MPH, the car stays around 2500 RPM then it jerks hard and the RPM's shoot back down to about 1000. I was thinking this problem probably can't be from a bad cat. Could it? or maybe a new MAF is needed?

Thank you guys again for your time and help.

 

I live in MA too, my mechanic helped me rid off that same code, for about $600. Can't guarantee that yours will be the samething but you could give it a shot, there are cheaper things you can do before putting in a new cat... Where in ma do u live?

 

I live in a town called Ashland. It's right next to Framingham

 

Oh I'm in worcester! U could come see this guy and see what he can do

 

If you live in CA then you must buy OEM cats at inflated prices to pass smog tests. Outside of CA you can buy cheap aftermarket cats to replace the CA cats. You can also buy cheaper O2 sensors (Bosch) online rather than the inflated OEM ones. $600 sounds about right for aftermarket parts and installation.

 

There are 3 things or a combination of the 3 things that could cause the P0420. Poor ECU program, bad O2 sensor housing or bad cat. I was lucky enough to get mine fixed under warranty and they fixed all 3. If you are replacing the Cat i'd also throw all new O2's

 

I would personally throw in new O2s before replacing the Cat, the sensors alone could be causing the code.

 

How many miles is on your car? And are you going for performane or just keeping it stock? If going for stock carstuff.com got plenty of pre cats and main cats for good prices, but if your going for performance get some OBX HEADERS OR CATTMAN'S...Cali smog sucks with the sniffed....Good Luck...you should be good since you in another state..

 

Thank you! yes, I am trying to keep it stock.

 

That would be great!

 

How much do you think all the parts would go for? (2 o2 sensors and a new cat) also, which brands would you recommend?

 

I agree. Replace the O2's before you go after the cats.
It's not the sniffer that's hard to fool its the visual inspection.
I'm honestly not sure what the parts would cost I would look at rockauto or if you want oem give dave b a call or check courtesyparts.com

 

Put in an o2 simulator. Took care of the same problematic code for me. Best 40 dollars spent to date....

 

But wouldn't it harm my car if I leave the bad cat in though?

 

O2 sims and headers...that's the route I'm going for, since I'm replacing my pre-cats and O2 sensors as well.

 

Nice nice

 

Before you do anything else, buy a $35 code reader on Ebay, and reset the codes. Then fill your tank with Shell Premium, buy 2 bottles of Chevron Techroline, dump them in the tank. Take it out for a nice 50 mile run and keep your rpm's up, i.e. lock out Overdrive.

I did that to my ALtima 3.5 when I got the same code, and it never came back, until I dumped a tank of Chevron in the car, then the code came back. I re-fil;led it with Shell, reset the code, and it never came back again. No joke. Sometimes that 0420 code can be from some very touchy sensors.

 

So what may be that bucking feeling I get while going at low speeds? If im going around 15mph or so and press the gas pedal so I shoot to about 25mph then let go, I get a loud jerk that I can hear and feel. Could this be cause of my clogged CAT?

 

So I have ignored my cat problem for a bit and now there is something I have to do. Do you guys know what would be easier? put in a new cat converter (if yes, then which brand would be best?) or do I have other options to get rid of it instead. What do you guys think I should do?