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Yes upstream is before the cat and in closed loop the ecu uses its inputs to control the mixture to that bank, is it the cause of your misfires? Maybe, but you are chasing your tail unless you start your diagnosis with a properly functioning 02 feedback system.
Yes upstream is before the cat and in closed loop the ecu uses its inputs to control the mixture to that bank, is it the cause of your misfires? Maybe, but you are chasing your tail unless you start your diagnosis with a properly functioning 02 feedback system.
Got it! Can I test it with out a multimeter or is that a must?
Just check the wiring and and clean/check the connector inside and out. If it checks out just replace it with a quality 02, if its original at your mileage it doesn't owe you anything. If you are going to keep this truck you should really get a scanner like the icarsoft then you can look at live 02 data, fuel trim, temp, ect ect, abs codes and srs codes, no more trips to the parts store and so much more useful than a simple code reader
I'll watch that with interest. I've never had a misfire from a bad, unplugged or missing O2 sensor so I'll have to add that to my list if it works. When I've had problems I've driven my truck in open loop and the result was a sooty tailpipe and horrible gas mileage.
The runs fine then goes badly scenario could indicate a clogged catalytic converter too, and heating it up might be the issue. I know in the video I hear alot more exhaust sound on the passenger side (but that could be the location of the mic and it would probably indicate a bad gasket or loose studs). If there is an exhaust leak that upstream O2 is going to register problems, if it works. And if you suspect a bad cat you can try running the truck a short time in the driveway after dropping the exhaust. It will chase all of the birds away and alarm the neighbors. But I'll tell you right now that the studs on the flange between the manifold and the y pipe are probably rusted and funky. I always have a little package of extra studs and nuts handy when I do that because they break, which always leads to cursing and banging on my part. Most auto parts stores have them.
I'm really disappointed that the brake cleaner didn't reveal anything. I had high hopes that a new gasket and some duct tape would have you fixed, as it has me in the past.
As the other poster noted the fuel system is in open loop when you start and should go to closed loop after a short period when it is satisfied that you are up and running correctly, and that's when the computers decide to start adjusting everything on the fly for variables such as fuel and air. Without a code reader it is hard to know whether and when yours is going into closed loop.
No I was commenting on the fact that I did not see any bubbling in the coolant overflow. I think you had mentioned earlier that was a sign of a blown headgasket sign.
Okay. Thanks. Well if you aren't losing any coolant and there arent any bubbles then thats good. I was being alert for any head gasket issue, and still have no reason to suspect it.
Got it! Can I test it with out a multimeter or is that a must?
My short input. Got engine light for over a year and went DMV to just fail it.
Had both O2 sensors replaced. 1 sensor got loose, did not click upon installation. My disco runs smooth on idle but after a 10 miles got rough climbing a low bridge. Received Ultra Gauge in time. Reset codes P0135, P0155 and P0134. This was wen the O2 sensor Bank 1 was not connected. Received Coil pack, ignition cable and plugs. Installed all new. RUNS smooth but not on highway speed. Throwing all misfire codes
Replaced O2 sensor Bank 1 with the Old Working sensor which I knew that works. Everything fine now. No misfire codes for 50+ miles YET! Like 2Rock said, O2 could be a reason. Also get an UltraGauge so you can see code alerts as it happens.
Well, I got 0441 code and its just a purge valve and its on its way to me.
Cheers and good luck!
Geez I missed it then. Better get those 02 sensors in order.
LOL! Didn't miss a thing. I just based it over my assumption that the tune up parts were all new. Made sure the coil packs properly grounded, grinded connections, applied carbon contact grease. All terminals clicked and snapped into place. Yes! checked vacuum leak with the cleaner with fire extinguisher beside me. Even had a P0420 pending code (Catalyst efficiency deteriorated - LH bank (NAS and EU-3 only). All codes not (YET) showing anymore at this time after the O2 replacement.
03-18-2016, 09:50 AM
