Bad Cat or what?????

[Chi Town]

Hey Everyone!

I have a 1997 V8 with 19.8k miles. I've only had it for about 4-5 months and just started driving it a few weeks ago due to the break in weather. I noticed that the car sounds like crap at idle!!! I also noticed that when I step on the gas pedal, it takes forever for the car to launch forward (especially after upshifting). I thought that it was something wrong with the turbos (boost) or fuel problem, but when I checked the exhaust, I found that the left side cat and tailpipe were cool to the touch. I can actually put my bare hand on the tailpipe after driving for 30-40 minutes!!! There is also an absence of an exhaust note from the left tailpipe ----SILENT. The right side cat and tailpipe are hot, but not as hot as I think it should be. Could I have a bad cat(s) or O2 sensor(s)? I just got my FreeScan from Marcus and have used it only at idle thus far. I got a knock sensor error of 1. I plan on taking it for a drive within the next day or two with the scanner runing to see what comes back, but I wanted to bounce the preliminary info off of you guys first to see if you can save me some headache, time, $$$$, etc,..... Any info would be greatly appreciated.

I've already begun to spec-out and price a custom Magnaflow exhaust system with hi-flow cats. I know that many Esprit owners complain about the weak-sounding V8, and I am hoping that this will help fix both problems. The way it runs now, any kid with a souped-up rice-rocket could kit my butt and go back to brag to all his friends of how he smoked an exotic!!! We all wouldn't want that to happen, right? (SMILE)



>>> Edited by Chi Town on Monday 2nd May 05:43

>>> Edited by Chi Town on Monday 2nd May 05:49

[zhastaph]

If the exhuast is completely silent and stone cold on one side then I'd be thinking more along the lines of ignition. The v8 Esprit has 2 coil packs, one that feeds each bank of cylinders, it's certianly possible that one of these has failed or the feed to it from the ECU has rubbed out on something. It's a pretty easy test, just pull one of the HT leads away slightly from the spark plug whilst the engine is running and you will hear it crack as it arcs to the plug.

If you want to check the cat also just pull it off and shake it about a bit and see what comes out. Other than fighting with corroded nuts it's only a 15 minute job to remove, there's a bracket with 3 nuts that attach it to the turbo and a bracket that attaches to the exhaust. Other than removing the connection for the O2 sensors {make sure you mark the plugs as their both the same} that's it and it can just be pulled out of the way.

[Chi Town]

zhastaph,

Thanks for your reply. When you say HT leads, you're not refering to the spark plug wires are you? Sorry, but I'm a novice mechanic at best, so you have to spelled everything out for me.

Thanks

[Dr.Hess]

HT = High Tension, an old (anchient, actually) term for High Voltage. As in Spark Plug Wires.

I would look at the cat. They should be pretty darn warm after running. If they are not, they are likely gutted or plugged. And they should both be the same. Try rapping on the cat with a mallet and see if it rattles.

I'm not familiar with V8 exhausts. Is it 2 pipes into 1 muffler into 2 pipes? Can one side be blocked off inside the muffler?

Dr.Hess

[zhastaph]

Yeah, it's 2 pipes in one silencer into 2 pipes out, they're both seperate so techincally one could get blocked, though I wouldn't have thought it likely, unless it had completely rusted and collapsed in on itself - ok I take it back, it is quite likely

You can run the car without the silencer and just the pipes off the cats pointing out, it isn't all that noisy either, in fact I reckon it sounds like it always oughta

[cnh1990]

If the cat matrix has come apart into pieces it can block the pipe perfs in the muffler

[Chi Town]

Anyone else with any ideas? Your help is GREATLY appreciated.