Light popped on this morning. checked out the code and apparently its with downstream sensor after the cat,or the cat...


Now....lately i have noticed a big loss in mpg.

Whats the best way of testing parts? for the cat i was thinking drive it around hard for a bit in the dark and see if its glowing.

Can someone tell me how to check the sensor with a meter? I cant really afford to throw parts at it right now. Thanks. all o2 sensors and cat was replaced about 5 years ago.

btw 03 ram 5.7

 

I just did all four 02 sensors in my 06' 5.7 today. They are surprisingly inexpensive. About $25.00 for the factory spec Bosch units. Auto Zone had them in stock.

Based on the fact you are seeing a big drop in MPG, i would have to say it's the 02 sensor and not the cat. So you are talking about a $25.00 part and about 20 minutes of easy labor. Just grab a 7/8 wrench or 02 Sensor socket and slide under your rig and make the swap.

But ill let someone chime in to confirm.

 

I maybe wrong but I thought a lot of people were having problems with the bosch sensors

 

It could definitely be your O2 sensors but also check to see if you have any holes in your exhaust system as well...that could make your computer throw that code as well...it did to me...I check my O2s and they were all still good to go and so i then check my exhaust system and found a couple holes in a few welds...I then welded the holes shut...I disconnected the battery...re connected and started the truck up and I was good to go again...hope you figure it out buddy...

 

Actually, based on a recent experience with one of my other vehicles, if you notice poor mpg and also get a P0420, that may indicate that your CAT has gone bad. If you get the code with no drop in mpg, it could just be the sensor. My vehicle was fine on mpg but i got the code several times. Replaced the sensor and no more codes. Its worth a try to just swap the sensor at first. Best to buy them online - usually a big difference in price. In the last year, i have investigated o2 sensor related issues for 3 different makes and Bosch has a bad rep for every single one of them. Find out who the OE maker is and buy theirs. The sensor behind the cat is the one that throws that code. The one in front of the cat adjusts AF ratio and is more likely to throw a P0134 or P0135 code. I am replacing the front sensor in my mother in laws GM car tomorrow for those codes.

 

yep, about 90% of the people who use them in Chrysler vehicles report a CEL with them. Always have. I made the mistake of buying a pair for the ex's Grand Cherokee about eight years ago myself. Popped a CEL within 10 miles. Pulled them and used Mopar ones and the CEL went away.

There are hundreds of posts on DF about problems on Rams using Bosch sensors...

 

Ive been so busy with work,i forgot about checking the cat to see if it was glowing last night. The sensors are $65 each a my local auto store,which is a bosch..Ehh.

Im wondering if it is the cat,as my wot power seemed to have gotten a little lazy.


Off topic :

Ever since i purchased it back when it had 65k miles on it,ive always had lag in throttle response in the gas pedal. Had my mothers pastor who is a mechanic put it on the computer a few years ago and fixed it,its been doing it again for the past year. I cleaned the tb. its a electronic issue. Is there a sensor in the pedal assembly that needs to be adjusted etc?

 

Yes there is a procedure to re-calibrate the sensor (see the FAQ section) but I'd suggest you ground the throttle body it'll take care of that fly-by-wire lag...

 

Ground the throttle body? Ground it where? Its been such a long time since ive removed it i dont remember if theres a bolt i can use,where would i ground it?

 

Check this thread for ino on the tb grounding.

https://dodgeforum.com/forum/3rd-gen...ng-the-tb.html