Getting cat's replaced...

Discussion in 'Performance & Fuel' started by SoundZman, Sep 28, 2011.

  1. SoundZman

    SoundZman Rockstar 100 Posts

    is $250 per catalytic converter (out the door) a good price for this?

    Sounds pretty fair to me...
  2. silveradotrailblazer

    silveradotrailblazer Epic Member 5+ Years ROTM Winner 5000 Posts

    Is that installed? I paid $98.00 each for my Magnaflow oversize cats. Installed myself. Even installed, $250.00 each sounds like alot.
  3. Metaluzc

    Metaluzc Rockstar 4 Years 100 Posts

    Is that for OE/OEM replacement ones? You can get aftermarket "hi-flow" cats for cheaper like silveradotrailblazer said.
  4. SoundZman

    SoundZman Rockstar 100 Posts

    Unfortunately being in California, the smog laws are very strict and became even stricter a couple years ago. Therefore the cat's have to be C.A.R.B (California air resource board) approved and stamped in order to pass smog every 2 years. When my Catalysis Efficiency codes began last year the only aftermarket manufacture, who was applying and receiving CARB approvals, was Magnaflow's parent company. The approvals where vehicle specific, not cat specific, so they had to test and provide documentation for each vehicle. Today I know of another company (Walker) which has CARB approved cats for by Burb and so does Magnaflow.

    So needless to say hi-flow it completely out of the question. Which leaves my only options of; $250 installed per catalytic converter OR $700 from my local dealership for OEM cat (y-pipe, flange to flange).
  5. terryny

    terryny New Member

    That does sound like a good price if they meet CARB reqs. Misfiring can lead to converter failure... any history of this? A new converter will pass many tests with flying colors, only to fail prematurely with the infamous P0420.

    Often you can pass the 'check engine' part of emission testing by resetting the light and driving until the monitors runs. You can get the catalyst efficiency test to run much more quickly through a sequence of steps. Only problem is if you are on the threshold of pass/fail the test may run extra times before the PCM makes its 'decision.'

    Many people are rumored to have beat the catalyst eff test by installing non-fouling plug adapters in the O2 sensor bung (sensor 2 after the converter). Install the sensor inside the non-fouler. This spaces the sensor from the exhaust flow, causing it to 'read' differently than the front sensor. Note- when the cat ineff codes set it is because the sensors are reading real close to each other (means nothing is happening inside the converter). At a strict place of inspection (most people) would need to remove the non-fouler (after the monitors have passed) and reinstall the original way. Then drive down for inspection. "But how do I avoid the code flagging before inspection?" Drive as little as possible and avoid the sequence of steps that cause the monitor to run... or so the rumor goes.

    I'll look for the complete regimen of running the catalyst efficiency monitor if someone else doesn't have it handy. It's basically a warm engine... then stopping with your foot on the brake for roughly 2 minutes while in drive. This test must be run more than once... possibly many times.
  6. SoundZman

    SoundZman Rockstar 100 Posts

    Thanks for the info TERRYNY....but I can pretty much tell you exactly why my bank 2 cat failed. Just before moving out of state I began getting a Knock Sensor code for bank 2, I reset the code but it began coming back more and more frequently. Well I let it go until after I moved and got settled in (probably about 3 months), then I replaced both Knock Sensors. However shortly after doing so, I found the Catalysis Efficiency code rearing it head. In doing research on a knock sensor code I discovered the ECU has a built in fail-safe, it puts that banks a/f ratio into a rich condition, in which it begins dumping excess fuel down that bank. So leaving it like that for an extended period of time caused the cat to run much hotter then normal which tends to breakdown/melt the internal metals.

    So in testing the temperatures my mechanic said he measured a 40 degree difference on bank 2 (inlet vs outlet) and a 60 degree on bank 1. Since he's dropping the exhaust and the other cat isn't performing quite up to par, I figured to just replace both and throw on a Flowmaster muffler. Replacing both cat's will also help to keep the exhaust balanced...maybe that's just how I rationalize it to the wife :great:
  7. Rockstarrchevy81

    Rockstarrchevy81 Rockstar 3 Years ROTM Winner 1000 Posts

    x3 they are way overpriced whom ever is trying to get $250 a piece for them you can find allot of high flow cat's online for allot cheaper.. i've heard that they really dont help out allot from others online but not 100% sure since i dont have them!

Share This Page

Newest Gallery Photos