Rough Idle/O2 Sensor Issues...HELP!!!
 

Forum first time user so hopefully you guys can help me out because i am stumped...:( I would say that i am Mechanically inclined but not a pro by any means ive been around/tinkerin on cars-trucks-tractors as long as i can remember.

I have a 04 Dodge Caravan 2wd with the 3.3L 137,xxx miles that i purchased a few weeks ago. when i bought it the check engine light was on for bank 1-1 O2 sensor as well as a few other things (air charge sensor-intake temp sensor) i purchased all the parts i needed at my local autozone to fix the CEL...this is when things got tricky.

Upon Replacing all the Parts and letting the van run for about 5 Minutes i went from having 6 CEL Codes to just 2. The first one being P0135 Upstream Oxygen Sensor-Heater Failure and the other being P0301 Cylinder one Misfire. I also Noticed that the van was Stumbling/missing upon Acceleration and idle Somewhat Noticeable in Park but very noticeable in gear. It Seems to get worse as it gets warm.

The O2 Sensor that i had bought from Autozone is a Bosch and after having the CEL come on after Replacing i Figured i got a bad Sensor so i ran and bought another.

I replaced the O2 Sensor with another Bosch O2 Sensor and before i started the van again i figured i should check the Misfire problem on Cylinder one. the Wires and spark plugs seem to be fairly new when i pulled cylinder one Spark Plug it was wet and smelled like gas (Fouled Plug) seeing this i was hoping the plug was bad but to make sure i swapped plugsWith Cylinder 3 With hopes that the CEL would follow the plug Confirming a bad plug which upon Pulling Cylinder 3 Plug it appeared to be good.

Now that i have swapped Plugs and put a new O2 sensor i Started the Van with hopes that the O2 sensor would be good and that Cylinder 3 would have a misfire code...Right?...WRONG!

So within 5 minutes of starting the van i get two codes the first being P0135 Upstream Oxygen Sensor-Heater Failure and the other being P0172 Bank 1 System too Rich. but no misfire code... van was still Stumbling/missing upon Acceleration and idle Somewhat Noticeable in Park but very noticeable in gear. It still Seems to get worse as it gets warm.

What do you guys think my issue is?

I have looked over the wire harnesses and everything looks to be fine. i also cleaned the Throttle body. The codes only trip when the van first starts up but if i clear the codes after the van is warmed up and let i run the CEL wont come back on but still runs crappy.

Below i will list the Bosch Specs:
Product Details

Part Number: 15512
Weight: 0.28 lbs
Warranty: 1 YR
Application: Up-stream sensor (located before catalytic converter)
Notes: O.E. type
Exact Fit
Oxygen Sensor Connector Type: OE Connector
Oxygen Sensor Type: Narrow-Band Heated

I Noticed that the other O2 sensor Autozone offers(More Money) is a different type. Would that make a difference? (specs Listed below)(I have not tried this sensor)

part Number: 234-4410
Weight: 0.25 lbs
Warranty: 1 YR
Application: Up-stream sensor (located before catalytic converter)
Notes: O.E. type
DENSO is the OE Manufacturer / Oxygen Sensor
Oxygen Sensor Connector Type: OE Connector
Oxygen Sensor Type: Narrow-Band Non-Heated

As you can see the Bosch is a Narrow band Heated and the Denso is a Narrow Band Non Heated.

Do you think this could be my issue and also do you think that the O2 Problem is causing the other Problem with the Rich condition and the van Stumbling/Running rough??

Any help on this would be extremely appreciated!!!!!

P.S. Sorry for the lengthy thread just wanted to give as much info as i could.

Thanks,
Mike

Many, many, many people have had issues with Bosch, not just with Dodges but other manufacturers as well.

Yea im wondering if thats half my problem im considering buying the denso sensor and see if that helps at all?

Its throwing me off that the bosch has a heater but the denso doesnt i dont understand why they would be different if they are both for the same vehicle?

Thanks

o2 Sensor
 

So did this resolve the issue, I have just gone trough the exact same issue and replaced my O2 sensor twice, still reads as P0135 Upstream Oxygen Sensor-Heater Failure, with my last sensor bought direct from Chrysler....

Cheers

Wiring and connector are always in the mix for a code like this. Have you inspected them carefully?

Getting power at pin 2 and ground at pin 1 at the sensor connector?

The o2 senor has a heating element ...check your fuses in the engine bay. Look for the one labeled o2 heater...if theo2 sensor isn't hot enough it won't record gases right. Throws a rich mic error code.

I have same as others bank 1,mis firing jurking when warms up .
the only thing I have not done is changing the o2 sensor should I change both o2 sensor?

You can never use Bosch O2 sensor on Dodge use original O2 sensor you can buy at Napa they are Delphi I think that’s how you spell it anyway Bosch does not read right on most Dodge Vehicles

So are you saying that if I installed a Bosch O2 Sensor it could throw up a code even if it is for a different thing?