j2mc

In a previous message I mentioned the CAT light was constantly flashing, I thought it was a sensor but thought, well I can go get my emissions test done and that would tell me if I have a failed CAT or its just a sensor. It failed emissions, but doesn't look like a failed CAT:

HC(PPM)
MAX | Measured
198 | 209
183 | 210

CO (%)
MAX | Measured
0.81 | 3.15
0.71 | 3.17

NO (PPM)
MAX | Measured
1742 | 248
1542 | 241

So I have a little high HC and really high CO and really low NO. From what I have read this means my engine is running rich but the low NO means the CAT has not failed. Can someone confirm that for me? Anyway I have ordered a new O2 sensor, and I will be changing the air filter, plugs and oil, is there anything else I should check? The only running problem I have noticed is when coming to a complete stop the engine rpms drop until it almost dies then come back up around 700 rpm(it has actually died on me twice).
Thanks

yodasfro

Add a couple cans of dry gas to the tank and pray?

AK_92_V8

and got a o2 sensor for my cel and a knock sensor. If you have a cel pull codes. After those 2 new parts it was a totally new car WAY more power and fun.

V8QinNJ

....give the ECU a faster and cleaner signal. The "extra" wire is for an additional ground. Most who do this conversion add the new ground to the same point as the ground for the rad fan on the drivers side strut tower.

V8QinNJ

Idle Stabilizer Valve. (Round thing at the front of the motor). But if you can pull the codes you should have a much better idea of whats what.

j2mc

No CEL, although no CEL even on start so I think I have a missing or burnt out bulb. I will go pick up the parts for a test light today and see if I can get any codes to blink out.
Thanks

j2mc

Thanks, I will check that out, should I just pull it off and clean it with brake cleaner or TB cleaner?

V8QinNJ

Yes, but after you get all the crap in there cleaned out use a bit of WD in there to help lube the assy.

5000Q86

if NOx is that low, which is waaay low, and HC is high id suspect that there is insufficient burning of fuel, or insufficient delivery of air to the engine. both cause rich conditions, which you menthined, and both lower the temperature of the engine. the tips of the plugs should be a golden brown color and dry. click the link to compare your plugs to each picture. plugs tell EVERYTHING about how an engine is running.

also could be a faulty thermostat that isnt allowing the car to reach full operating temp. keep an eye on the coolant temp guage, and to be doubly sure, stick a thermometer in the coolant to see what its reading. factory thermostat opens at ~185 degrees F. to test the thermostat, pull it out when the engines cold. it should be closed. drop it into a pot of boiling water and it should open up in less than 30 seconds.

The RPM drop says Idle stabilizer to me as well.<ul><li><a href="http://www.mkiv.com/techarticles/read_plug/plugdiag.jpg">http://www.mkiv.com/techarticles/read_plug/plugdiag.jpg</a</li></ul>

j2mc

Ok, I pulled codes last night, for the ECU I only got:
2342 - Oxygen Sensor Signal (voltage) is not changing up and down, (Shown for ABH Engine Only)

Weird thing is I have a 90 so I'm pretty sure I have the PT engine, but anyway I had my new o2 sensor and went to unplug the old one and found out one of the wires was not plugged in! The sensor looked old(probably original) so I decided to replace it anyway. So far haven't got a code again and....WOW I thought this thing had power before...I am really gonna get a ticket now.