i have an 03 ram, 4x4 QC. as noted with hemi
mods:
AEM cold air, Superchips programmer, and a magnaflow muffler (all packing is long gone! loud as heck. will never buy another packed muffler from magnaflow! this is my second one, and after in less than a year and only a few thousand miles it is garbage)

anyhow, at idle the exhaust looks like it is a diesel (pig rich) as well when i am driving you would think it was a diesel that I was driving with black smoke spewing out!

when i check codes i have 2 recurring codes.
1. P0171 - Too lean Bank 1
2. P0138 - O2 sensor High Voltage Bank 1 Sensor 2. my understanding is that Sensor 2 is the downstreamO2, which shouldn't affect the way it run, merely a check and balance for emissions.

Needless to say mpg are terrible!! and at 3.65/gallon...ouch! lol!

have you had this, and was a simple O2 sensor change? plugs have only a couple k on them. I plan on pulling the throttle body and give it a cleaning as it has not been cleaned in a LONG time/ many miles.

any tips or help is greatly appreciated.

time is a premium, so I figured it wouldn't hurt to ask. anytime saved means it can put put towards the family, and the Camaro, lol!!!

 

Due to the lean condition, it is probably throwing off the rear O2 sensor. Perhaps a vacuum leak.
Usually that P0171 code is not caused by a bad O2 sensor. Have you tried going back to the stock tune to see what happens? Maybe unhook the battery for awhile to reset the PCM? How many miles on the truck? Might be time for a new PCV valve.

 

82,000 miles.

PCV not recently changed, I will check for vac. leaks. i will go back to stock tune, but onyl minor concern is tires are 33.25 " tall a fair bit bigger than the stock tires that came on the 20" rims.

Thanks, fortunately the truck is not my daily driver, so i will swap PCV, dump PCM, and put stock tune in and see what happens. as well as clean throttle body.

I will even pull a couple of plugs to see if they have gone to hell in a hand bag. it is supposed to warm up a bit ....finally. I can crack into her. i may need to put another set of plugs in???

any idea if the trucks have any historical issues with their ECM/PCM's ?

thanks for your input!

 

As a rule of thumb, if I get ANY code that is generated by an O2 sensor, I replace that sensor FIRST. They are cheap and tend to be the culprit more often than not. Even if it doesn't fix the issue, you've ruled out the O2 and confirmed the code it's generating to the PCM is accurate.

Returning the tune to stock is not a bad idea for troubleshooting purposes, especially for a lean state, because the both the tow and performance tunes advance timing quite a bit (especially so with the perf tune) and advanced timing causes an engine to run lean.

As lxman1 states, also look for an evap leak, will also lean you out. Another place to look would be around the exhaust manifold, a leak there will generate a lean code by the forward O2 sensor and the manifold bolts are known to break...

 

Whatever you do, Make sure you get a Chrysler O2 Sensor!!!! Do not buy any other brand!!! The Chrysler ones are the same price as the Bosch and all the other ones!! I replaced both of mine. The upstream one went first and I bought 3 Bosch O2 sensors before I relized that I need a Crysler one!!!! Dont go through the pain and mysery that I went through when my O2 sensor went bad!! BUY CHRYSLER ONLY!!!!!

 

broken manifolds bolts... been there done that, lol! early last year. fixed both sides.

i agree with the Chrysler sensor however, i just put that in last year as well.

i will start with the pcm and retune. I even threw in the economy tune...it didn't help, lol! (not that I expected it to)

 

if you only had the fuel lean code i'd say be looking for some sort of vac leak or fueling issue. But the second code is a definitive fault code with the O2 sensor.. downstream o2 on bank 1 (driver side) needs replaced without a doubt really.. I'd say get a new sensor.. reset PCM and see if the fuel lean code comes back

 

I've had no probs with the bosch 02 sensors since replacing 2 years ago.

 

Bosch makes most of the OEM sensors so the aftermarket Bosch sensors are just as good.

 

The wife and i were out eating last night and this guy hops in his Mustang and you could easily hear the ticking it has was related to an exhaust leak