I started having problems with my 8. I replaced the coils with the BHR ignition kit and replaced the plugs. She ran much better for a few weeks. Now I have a good idle, no power in the low rpms until I hit around 4k rpms, and a glowing red cat after driving. Even after 4k rpms the acceleration is better but rough. The cat glows even when I granny her. It's getting much harder to get her cranked now too. To make a long story short I removed the cat with the intentions of gutting it until my BHR midpipe comes in. I was surprised once I got the cat off because it looks fine to my untrained eye.

Would it hurt if I cranked her up to see how she ran with the cat completely off? I just want to start her and give it some gas to see if it sounds better. I'd like to know if the cat was my problem before I gutted a potentially good cat. Any help is appreciated.

FWIW, I've checked all of the coils and plug connections. Everything seems good and tight.

 

The only thing it will probably hurt would be your ears. You shouldn't really go racing around with no cat on but I cant see it hurting anything.

 

Why remove your catalytic converter and do you want the cops stopping you all the time because of that loud noise? Just wait for your BHR midpipe, then you can remove it without the hassle of driving loud and waking up your neighbors, lol

 

If I understand your question, you just want to remove the cat, start it and let in run in the driveway, give it a rev to see if there is a difference, it wont hurt the motor,but it will be loud, very loud. With the cat, just because it looks oki doki doesnt mean it is, some fail completely and disintegrate , mine was empty when I removed it (BION) , some clog up and some fall apart internally and rattle.

 

I believe you should be good for warranty work. Warranty on emissions is 8 yrs/80k miles.


With that said. I have a question that is somewhat related to the topic. I have suspicion that my catalytic converter might be going also. No significant evidence other than minor symptoms such as a slight rasp, minor rattling, some sulfur smell, and some glowing by the O2 sensor after a spirited drive. I have not taken the cat off to see, but WHAT IF there are no signs of a failing cat by sight? The question is how will the dealership diagnose a failing cat? What symptoms need to be met in order to have the catalytic converter replaced?

 

 

Depending on the dealership and your relationship with the dealerhsip it might be a difficult fight to get the cat replaced. I have seen numerous posts about the dealership saying to replacing the plugs and coils first to see if that helps and then finally agreeing to look at the cat. If you know your dealership staff well maybe you can get them to inspect the cat right away.

 

Fortunately I have a replacement set of coils, plugs, and wires. I do not have a receipt for the coils, but the plugs and wires yes (though they are from a vendor).

 

You're correct I just want to crank it up and rev it in my driveway. Nothing crazy. It should only take a second. I want to make sure the cat is the problem before I gut it. No sense in ruining the cat if it's good.

I'm at 87k.

 

With the cat off, you will be spitting flames and burn something in the process. Not advisable

 

That's what I'm afraid of.

 

Not necessarily. As long as he doesn't rev the **** out of it, he'll be fine. I've started mine with the midpipe off and gave it a few revs just for ****'s and giggles.

OP, if you do it, stick with low throttle inputs and don't rev the **** out of it. Since your having mostly low rpm issues, this shouldn't be a problem. Lots of throttle and higher rpm is what will get you into the trouble yiksing is talking about. Don't drive it and it will be deafening.

 

Depending on the dealer, they may be able to do a sniffer test. Make sure you run the hell out of it before you get there so it's glowing and stinky. If you're smelling sulfer, that's a good indicator that it's going bad. They should be able to smell it too and recognize the smell.

 

Well, I'm done. I checked everything and ended up gutting the cat. Car runs much smoother now. I still have a little bit of hesitation when I start in first gear while the A/C is running wide open on recirculate. Starting her up is better but still takes a bit to get her fired up. I think it's time for a compression test.

Also, I'm surprised how she sounds. Honestly it's not much different from running with a cat. Of course high rpm shifts can produce a loud pop.

 

I once saw an RX3 shutdown a 396 Chevelle on a open header "noise" challenge.
The 396 was loud, but the local Police had reports of a jet crashing when the RX3 took it to 12,500 rpm.

 

hahahaha. That's an awesome story.

OP. Turn off your AC and recirc. Do you still have the stumble? Most likely it is the engine trying to keep up with running the combo at idle. pretty typical in most cars with it on to recirc.

 

When I attended IMSA races in the early 80's, sound controls weren't in place yet at racetracks. RX3's and RX7's ran with open exhausts. They were so loud that my ears hurt as they went by.