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Old 11-10-2006, 11:00 AM   #1
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Recently I installed a new upper intake after my original one blew (84,500 miles) and I know that all the anti-freeze drained into my cylinders therefore anti-freeze getting into my catalytic converter. I thought that driving quite hard would push all that sh*t out of my converter but I don't know if it did. I reset my Check Engine light a couple times for (Catalyst operating under threshold) and it keeps popping back on. Is there a way to clean out a converter or do I have to either 1. deal with the light or 2. get a new converter. If its a new converter, what is the average price to do it myself, and, how difficult is it to do in my garage? Also, my car tends to shake when at the speeds of 55-70mph and when stopping slowly it seems like it pulls, the brakes are new, the alignment is perfect at all 4 points. I have also rotated the tires recently and it is still doing this. If it was bad balancing it is pretty ironic that all 4 tires would be out of balance at the same time, isn't it? When I did brakes I did not put new rotors or get them turned seeing as they are high performance bendix rotors with only 40,000 on them. Could the rotors be warped...would them being warped cause this issue.

Thanks in advance for the help guys.
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Old 11-10-2006, 11:05 AM   #2
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Nick..

I wonder if your cat is bad or the O2 sensor got messed up from the coolant.

On the vibration, it would be worth having the tires balanced, the pulling does point toward a caliper or brake line hose not releasing. Mileage doesn't matter, heating and warping can occur on any rotor. If a caliper or line isn't releasing, that would heat up a rotor and could lead to warping.

Does one wheel have more brake dust than the other?
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Old 11-10-2006, 11:08 AM   #3
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wouldnt the o2 sensor come up with the check engine light instead of bad catalyst? i' getting new tires in about a month so would it be worth paying for a balance?
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Old 11-10-2006, 11:10 AM   #4
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Well, how about we address one item at a time? lol.

From the sounds of things, you just may have damaged your CAT. It'* not too costly to buy a hi-flow online, but you will need someone with good welding skills to install it. A direct fit Cat for your year is very costly, so most buy the generic fit and have them cut and pasted at a local shop.

A muffler shop I use offers the complete hi-flow Cat installed for $129, which is a bit more than buying online and installing on the cheap, but quicker and less grief, especially if your local shops have policies against installing customer-supplied parts.

Take a look at carsounds . com for an idea or search here for hi-flow cat
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Old 11-10-2006, 11:17 AM   #5
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Your CEL is always a reading from the O2 sensors, so a bad O2 sensor could just as easily throw that code as a bad CAT. It wouldn't surprise me if both were bad. Remember that the reading that tells your PCM about CAT function is the second O2 that resides in your exhaust pipe after the CAT.
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Old 11-10-2006, 11:17 AM   #6
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the local shop by my house will install a customer supplied one for $75-100 depending on if they have to change pipes. Are these high flow converters online direct fit? Is it even worth replacing?
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Old 11-10-2006, 11:22 AM   #7
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english please lash
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Old 11-10-2006, 11:23 AM   #8
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That'* a lot for installing a CAT, IMO. We got Don'* generic fit installed for $45 labor.

Like I said, the direct fit CAT system is expensive, in the area of $300+ and I have not found them to be readily (if at all) available for the '97. If you did want to go that way. it is basically a bolt-on at that point.

The generic fit CAT for our year includes the O2 bung and is in the $60-75 range. Check your local muffler place for an out-the-door price as a comparison. You may find it easier to go that way.
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Old 11-10-2006, 11:28 AM   #9
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Nick, which part of what he said didn't look like english. We can clarify that part for you.
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Old 11-10-2006, 11:31 AM   #10
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Quote:
Originally Posted by lash
Your CEL (check engine light) is always a reading from the O2 (oxygen) sensors, so a bad O2 sensor could just as easily throw that code as a bad CAT (Catalytic converter). It wouldn't surprise me if both were bad. Remember that the reading that tells your PCM (computer) about CAT function is the second O2 that resides in your exhaust pipe after the CAT.
There are two (2) oxygen sensors in your exhaust system. The first one is in the rear exhaust manifold and helps (provides input to your computer) monitor your air-fuel mixture (A/F). An air-fuel mixture that'* too rich can damage the catalytic converter and will throw a CEL and code if severe enough that the PCM cannot correct for it.

The second O2 sensor monitors catalytic converter performance and will throw a code (CEL) if the converter is not working correctly (and sometimes if the sensor itself is bad).

Does that help?
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