MBMB

Okay, I pulled the cats. Nothing shook out. Cleaned up the CO sensor -- not much soot on the shell -- should I spray something in it to clean inside the shell? I didn't, but I'll have the exhaust off for a day or two to source stainless hardware.

Any other ideas? How does a car that is really running lean behave?

mpesik

Hello MBMB. Did you send the fog light lens? Curious. Mike. Thanks.

MBMB

Mike,

Not yet. My shipping department (aka my "managing partner," aka "my wife") has been out of commission after foot surgery. Shipping your fog light is on my list of things to do.

Gretch

Well your car may retard the ignition timing to keep from pre-detonation condition. It should also run warmer combustion chamber temps, but that may be a harder symptom to identify............Have you tried a wide band sensor?

Jim_H

Have you looked at your plugs?

MBMB

Gretch -- I haven't tried a wideband sensor.

Jim -- no, but I will. What am I looking for?

Jim bailey - 928 International

Mark I would be thinking possibly a failure in the injection circuit shutting off 4 injectors two on each bank (that would make for a whole bunch of extra oxygen ). The relay with lighted diodes does sometimes fail and can cut power to either batch of 4 cylinders or all cylinders . Carefully inspect that relay and the wiring near it .....it may have been "fixed" in the past jumpered . I think I would get it running again then deliberately make it run on 4 cylinders to see if that loss of power / change in exhaust note is the same as what you have experienced ( you can disconnect one of the ignition switch unit secondary stage in front of the radiator ) . By deliberately putting it into 4 cylinder mode you will also be able to see if the ignition monitoring relay lights up red or green and shuts off 1/2 of the injectors or NOT . I am doubting the veracity of the red /green diodes and am thinking your very rich running condition in the past may have been running on 4 cylinders . The car runs on 4 cylinders and feels a lot like a 944 !!! 160 hp but reasonably smooth since it is missing every other cylinder . The design of the late catalytic converter is three sets of ceramic honeycombs in each of the two large chambers and it is very rare for one to get plugged plus it functions like two cats in parallel . So if one "side" plugged up the other side should handle the flow up to maybe 1/2 throttle . I do not believe you have an exhaust issue .

Jim R.

Mark,
When my EZK relay was shutting down, not only did the car lose power, but the exhaust note changed as well. The red and green lights are very hard to see in daylight, but easy at night or in the garage/shade. My plug backed off making poor contact with the relay. A little contact cleaning later, the problem has been gone for about a month. Good luck troubleshooting.

Jim R.

MBMB

Jim & Jim,

I have tested my ICC relay as Jim B suggests (by disconnecting each ignition secondary stage), and it works fine. When I lost power the first thing I checked was the relay, and didn't see lights, but this was in daylight and I might just have missed it. I'll pull the ICC relay and clean the contacts and report back.

MBMB

With the car back on the road after pulling apart the exhaust and not finding anything wrong, I haven't been able to reproduce the Civic imitation it had been performing. I'm going to chalk this one up to air intake obstruction (plastic bag?) that fell out before I found it. Thanks, all. Now back to my previously scheduled overrichness problem . . .