Jooman07

Pulled the P0432 code from my 2000 the other day. So far, before this code even came up, I've changed both bank 2 o2 sensors because it was throwing a code for those. That has been maybe 4 months ago. I have a small vacuum leak that WAS throwing code but the light went away on its own and that code is no longer coming up. From what I read here, some were saying could be bad cats or an oil leak or maybe even an exhaust leak. I'm going to be pulling the plugs this weekend and take a look at them because I have noticed a slight shudder when at idle sometimes. Anything else I should check for while I'm gonna be poking around?

cliffpenick

98% of the time it is the cat that needs to be replaced with that code. You could try the heat test but i think they are hard to get to on those. If at the rear of the cat is hotter then the front then it is a good chance the cat is bad. There is also the vacuum test but that one you have to drill small holes in the exhaust to do that one.

gunmetal_nightrider

Shoot man when my cat went bad the whole thing rattled. Tap on cat, see if it makes noise inside. (It shouldn't)

Jooman07

I've had a car with bad cats before and yeah it rattled like a sum*****. I'll start with the plugs and work my way down.

cliffpenick

If it is rattling and breaking apart it could clog your exhaust and start making performance problems. Just be careful if it starts bogging down you need to replace it.

madmanmarty

How is your power,esp. Going uphill?
Gas mileage down?

Jooman07

It seems to bog down a little going uphill and MPGs I get about 200 miles a tank. So between 10-11 MPG. It burns rich also so new plugs and such may be in the near future.

cliffpenick

You definitely have a problem. You should address that before you burn your motor up. Sounds like they are restricting your exhaust which can be detrimental to your engine.

madmanmarty

Or pull the exhaust off prior to the cat and run it up a big hill again.
See how she runs.
Also check for your vacuum leak.
Please save yourself some money and verify bad parts before replacing parts to diagnose issues.
Let us know.

odgreen

Marty we don't talk about removing cats on here. ever.

Jooman07

So here's an update on what's been going on. I haven't had much time to look at anything due to some stuff coming up over the weekend. When I parked it yesterday the CEL was still on. I started it this morning and there was no CEL on. So I thought maybe the bulb burned out or whatever. On the way to work I was stopped at a light and while idling there the light came back on. So my question now is, would a clogged cat cause it the light to come and go like that? I believe it did this once before after I got the code pulled. Originally I thought the guy at Autozone just cleared it after he read it. I came back on the next day. I'm also assuming the light is for the same code as well. I'll have it read again when I get a chance.

One other thing I read about that code is if you have an oil leak this can also cause that same code. I have 2 minor leaks. One is at the bottom of the timing cover in between that and the oil pan, and the other is I believe on the firewall side of the valve cover gasket which leaks down onto the exhaust and burns off. It leaks a quart or so every few weeks. Once it gets warm enough and stays warm I'll be fixing those leaks. So, could the oil be leaking into somewhere and causing this CEL like to occur? Or should I still be thinking it's the cat? When the question was asked if it bogs down going up hills, yes it does but I am running larger tires on stock gears too. Yes the mileage is horrible also still. The bogging is still minor, it will downshift while going up the hill but usually not until it's almost to the top of it. And I will also point out that this is only my second XJ, the first one I never drove it on the roads or highways so I never go to experience what they drive like on public roads.

CCKen

Is this the exhaust you have (pic below)? It sounds like it by your description.

With a 2000 (0331 head) I would be concerned about coolant contamination of the O2S'. Coolant in the exhaust usually leaves a white coating on them.


On the other hand, one cause of a converter efficiency DTC is an upstream O2S being older than the downstream O2S, in that the upstream O2S gets lazy with age and the switch rate of the downstream O2S approaches that of the upstream O2S. The upstream O2S cycles about every 2 seconds and the downstream cycles much slower. If the PCM sees both O2S' approaching a cycle match it may think there's a Cat problem.


An exhaust leak can cause the DTC, as you mentioned.


Hope you are using NTK O2S'.

madmanmarty

Didnt

odgreen

"put in a cat delete pipe" yea you did

Jooman07

Yeah that's the setup mine has. I'm not losing coolant that I know of and when I removed the old ones and replaced with NTKs they were covered in soot from what I think is from burning rich. One is "older" than the other cause I didn't change at the same time. But it's only by a few weeks.