Since this is the V6 its probably burned valves or cracked heads like Funair said. Well known issue with the V6.

Any other motor, I'd say bad 02 sensors or sensor wiring. You can only use Denso or NTK on a Dodge Ram, no other brand will work properly.

 

I didn't believe this until I went through it...


I clogged two cats using a Bosch ... I put in NTKs two years ago -- no problems!! And way better mileage

 

Ok. Let me ask this. Would burnt valves produce rediculous sniffer emissions output?

My tailpipe emissions are awesome

 

can I jump in and ask if a new set of NTK O2 sensors put into a working 5.2 engine with 175K miles on it improve mileage? Not sure what is in there now, but a $70 investment from Rockauto for new sensors is not out of the question. AM I just asking for trouble... if it's not broke don't fix it is usually my motto.

 

At least replace the front one. The rear O2 sensor really is just there to make sure the cat is installed. The PCM uses the front O2 sensor to dial in the fuel mixture. If you have a Bosche sensor or a old sensor with over 100k miles on it, I'd replace it with a new Denso or NTK.

NTK is factory. Personally I only install Denso on Dodge and Ford both. I get better performance and good milage from these. Thats just me, YMMV.

 

If memory serves it was not excessive emissions that led Funair (and others) to diagnose cracked cylinder heads, it was rough idling and lack of power. I'd suggest you appeal to him directly as he has been though this and has better information than I can provide.

At this point I suggest you do a cylinder leakdown test using a compression tester (cylinder leakdown gauge). You can probably rent one for the day from Autozone. If all cylinders pass cold, I'd run the engine up to full temperature and then test again. This is, as I've already said, a well known issue with the V6, the 5.2L and 5.9L engines don't seem to experience this issue.

 

Gotta love this forum! I had sent to Rock Auto for new upstream Bosch oxygen sensor but read here not to use them. I sent for another NKT(NTK?)one and installed it. With 100,000 miles on the van it runs like a new one! I had replaced plugs, wires, distrib cap, rotor, coil trying to cure the hesitation and cutting out I was getting. Keeping fingers crossed!

 

Thanks blackvan....


yes you are correct - horrible power, weird idle, and unexplainalbe misfire codes...
After I changed the heads, and install HS RR, I got (it felt) like 40 HP back...serious

 

Let us know what happens jimbo74

 

I am done with the van. Really don't care about it anymore. I got a new vehicle....

I didn't have a lack of power, or a weird idle.