Hi All,

To start, I've been a big lurker at this site, this forum has been a game changer for me and I have learned so much about engines/mechanics and how my truck works thanks to the awesome people on this forum sharing so much. So thank you for that!

I've had this engine code on my truck ever since I put a new manufactured engine in it. I figured its something I missed as when I drove the truck before it died with the old engine, the engine light never came on, even when it died the engine light didn't come on haha.

I drive a 01 Ram 1500 5.9 4x4. The trouble code reads out as Heated Oxygen Sensor (HO2S) 1, bank 1 - slow response. Looks to be the o2 sensor before the catalytic converter.

I changed the O2 sensor before the catalytic converter months ago and that didn't do anything. I think I installed a NTK(think that's the brand). I checked the wiring to the O2 sensor, and the harness all the way back to the ECM and it all looks fine. I had a pretty bad exhaust leak from the exhaust manifolds but have since blocked those up with some high heat silicon, not entirely sure if I 100% it. I did have a different engine code for that, that has since disappeared after the silicone job.

I've read it could be the MAF sensor, but I don't think this year dodge uses one. I also read it could be the IAC, or a grounding issue, I have no clue and i'm out of answers and money at the moment.

Any insight would be much appreciated!

 

Do you happen to have an OBD2 tool that can graph the O2 sensor readings (many of the bluetooth/phone ones can)? That might yield some clues. Also try disconnecting the upstream sensor in question and see if you get a circuit code that matches the sensor location. Is the truck federal or CA emissions ?

 

I just received a OBD2 reader today. I could see the voltage of the o2 sensor responding immediately when I pushed the accelerator. It would constantly jump between .05 volts and .94 volts on its own consistently, when I accelerated it would go past .96 volts.

I checked the emissions test, it lists out 11 systems out(misfire/fuel system/components/catalyst/heated catalyst/evaporative system/secondary air system/a/c refrigerant/oxygen sensor/oxygen sensor heated/EDR system). All of them passed except the catalyst 'did not pass' and Evaporative System 'did not pass'. The oxygen sensor and the heated oxygen sensor passed.

I'll disconnect the sensor tomorrow.

I live in Canada so I assume its CA emissions.

 

Did you clear the code when you replaced the parts(02)?

 

What brand O2 sensor did you install?

 

So many times in hopes it won’t reappear.

 

NGK with the square pigtail connector.

 

Sounds right, in closed loop the PCM varies the fuel amount a little and wants to see the O2 sensor voltage changing. No idea what triggers "slow response", let me dig.

CA = California emissions. These trucks have a different O2 sensor configuration.

 

Thanks, any suggestions will be awesome. I'm stumped.

I've read it could be an ECM issue. I hope not though, hard to get ahold of those nowadays.

 

Find anything on this?

Could it be from the intake keg failing? I’ve seen some posts on here saying it can cause multiple codes.