ATTN: Injection/ECU/LM Gurus!!

[BIGBRUDDA]

Yeah I think I'll get another O2 sensor. See what happens. While this one is still warrantied at Autozoneeo
And install a 4 guage ground. Mebbe even drive a copper stake in the frame. Even though they all have tested less than 3 ohms.

[TopDollar69]

3 ohms or .3 ohms? 3 is quite a bit for a ground in my experience. It may also depend on the meter being used.

[Clay]

And yes the O2 signal "toggles" normally at sub 7PSI conditions. 90-108mv @idle , and up to400+mv puttin down the street.

that actually seems lean to me as well. I would expect the centerline of the toggle to be around 0.5 volts at idle, ie around stoich.

[badandy]

Yeah I think I'll get another O2 sensor. See what happens. While this one is still warrantied at Autozoneeo
And install a 4 guage ground. Mebbe even drive a copper stake in the frame. Even though they all have tested less than 3 ohms.

I got a almost brand new Nippondenso that I will try to remember and bring with me...along with a fancy tap setup for your narrowband

[IROCNOROLL]

3 ohms or .3 ohms? 3 is quite a bit for a ground in my experience. It may also depend on the meter being used.

3 ohms is high for grounds. Best to test grounds by voltage drop rather than ohms. Especially when the issue is a small voltage circuit like a narrow band working at 1 volt and less. Maybe try another dvom to see if the readings you have so far are repeatable. Chasing ghosts because of bad equipment can suck.

As was pointed out before here, light cruise 02 voltages should toggle 1-200mv to 8-900mv. If they are running at less than 600mv, then there is either a resistance to ground on the 02 sample circuit, or the new sensor your using is tweaked or contaminated. Nail down that issue first.

[IROCNOROLL]

Unplug the 02 cell thats in there now, and try running it. And leave your DVOM connected at the LM where you have been taking your 02 readings. See what happens and post back.

[Tony Hanna]

Unplug the 02 cell thats in there now, and try running it. And leave your DVOM connected at the LM where you have been taking your 02 readings. See what happens and post back.

If memory serves, the ECU should drive an open O2 signal input up to approx .5v and hold it there right?

After trying that, you might also take a reading at the sensor itself while it's unplugged (will take longer to warm up). I need to reread the thread, but I'm leaning toward agreeing with the guys that are saying your sensor is probably pooched. That or a wiring issue between the sensor and the ecu.

[BIGBRUDDA]

YOU GUYZ R DA SCHIZZLE!! Gonna rerun grounds,swap O2 sensor, maybe rub on the MAP circuit.
Tony ya need ta get here for TURBOPALOOZA.Fun wknd ,lovely drive up the AA highway!

[badandy]

If memory serves, the ECU should drive an open O2 signal input up to approx .5v and hold it there right?

After trying that, you might also take a reading at the sensor itself while it's unplugged (will take longer to warm up). I need to reread the thread, but I'm leaning toward agreeing with the guys that are saying your sensor is probably pooched. That or a wiring issue between the sensor and the ecu.

Tony,

Want me to give you a ride to Turbopalooza? I'm coming your way bro I should be scooting through WV on Friday around 1 or 2. The only downside is if I break the car you gotta help me fix it

...just kidding...uhhh, I hope!

[Tony Hanna]

YOU GUYZ R DA SCHIZZLE!! Gonna rerun grounds,swap O2 sensor, maybe rub on the MAP circuit.
Tony ya need ta get here for TURBOPALOOZA.Fun wknd ,lovely drive up the AA highway!

Keeping my fingers crossed that it works out for you.

Tony,

Want me to give you a ride to Turbopalooza? I'm coming your way bro I should be scooting through WV on Friday around 1 or 2. The only downside is if I break the car you gotta help me fix it

...just kidding...uhhh, I hope!

Thanks for the offer!
I need to talk to John over the weekend, see if maybe he wants to go as well. If he does, we might end up driving the Caddy up Saturday. I hate to go to an event like that without a car to run, but it would be nice to finally get the chance to meet you guys in person.

[badandy]

Keeping my fingers crossed that it works out for you.


Thanks for the offer!
I need to talk to John over the weekend, see if maybe he wants to go as well. If he does, we might end up driving the Caddy up Saturday. I hate to go to an event like that without a car to run, but it would be nice to finally get the chance to meet you guys in person.

Hell, just race my car...I'd probably rather drink beer and hang out anyway

[badandy]

YOU GUYZ R DA SCHIZZLE!! Gonna rerun grounds,swap O2 sensor, maybe rub on the MAP circuit.
Tony ya need ta get here for TURBOPALOOZA.Fun wknd ,lovely drive up the AA highway!

I dug out the almost brand new NTK ( I thought it was a nippo ) 4 wire O2 to bring you. I'm sure this sensor is much better than the autoparts store stuff you are messing with.

Along with that is the narrowband sensor tap that is a plug and play...it's pretty sweet!

[BIGBRUDDA]

I'm gonna get a denso today and try it. They owe me one anyhow. I may even question their moral compass!

[Clay]

Go Mopar OEM.

cant go wrong with Mopar OEM! More money, less problems

[badandy]

Go Mopar OEM.

cant go wrong with Mopar OEM! More money, less problems

Which I believe is NTK

[BIGBRUDDA]

OK guyz da latest news is: Friday I got another O2 sensor(all they had was BOSCH). On the ride to the parts store I noticed whenever I applied the gas pedal the O2 went Negative -. Hmmmm!
I get to the garage ,check TPS wiring (its correct) and signals 4.85 vdc supply, 3.87 vdc @WOT. So it tests OK.
I ringout all grounds .3 ohms was highest.
I run all new MAP sensor wiring( add a tap for monitoring). I was suspicious of the firewall penetration.
Double check all LM connections.
Remove the bad O2 sensor(the bad "NTK" sensor) as it turns out! Install the new Bosch.
Start it up, good readings on the DVOM, it idles cold around 150, hot searches tween 30-500. Go for a test drive. Drives ok below 7PSI. The O2 searches up&down goes as high as 850, as low as 15. Still goes rich at 7 PSI ,but not as bad. reads 0 on the DVOM.
I install a spare Power module I have, jes to see what happens. Cause I'm thinkin "switching problem now"

It runs about 1minute OK. Then starts sputtering coughing and backfiring. It acted like "sudden death", or overboost once or twice. At sub-boost driving around the block! Had my hand full just keepin it alive! Last turn ,almost back home, it dies for about 5 seconds then ................KABOOM!!! sputter, sputter, WHAAAAA! Got home took a look at it .BLEW UP MY MUFFLER!! tore the whole end out of it.
I replace the old powermodule , starts up, runs OK. Only now it sounds like a Fart can HONDUH!! Parked it. I'll deal with it later.

[Tony Hanna]

That's really strange that the O2 volts would drop to 0 when the car is obviously running rich. Any chance you could go for a drive with the sensor unplugged from the wiring harness and the DVOM connected to the sensor? It'll take awhile for the sensor to warm up without the heater getting power, but the results from that should help narrow the list of possible causes down some.

[mock_glh]

It runs about 1minute OK. Then starts sputtering coughing and backfiring. It acted like "sudden death", or overboost once or twice. At sub-boost driving around the block! Had my hand full just keepin it alive! Last turn ,almost back home, it dies for about 5 seconds then ................KABOOM!!! sputter, sputter, WHAAAAA! Got home took a look at it .BLEW UP MY MUFFLER!! tore the whole end out of it.
I replace the old powermodule , starts up, runs OK. Only now it sounds like a Fart can HONDUH!! Parked it. I'll deal with it later.

Sounds like a chunk of the cat broke loose and was blocking the muffler. Or maybe someone punked you with the old 'tater in the tailpipe trick. Once the muffler blew the thing could breathe again.