This is my first forum post so bare with me. I’ve been having some pretty annoying problems with my 2006 Dodge Charger SXT 3.5l and I thought it would be very beneficial to hit some forums before spending the money at a mechanic. I only have one car and a very important job so if I can fix it on my own I will.



Anyways, to the tea. Just a little under a month ago my car started idling pretty rough. As in it would vibrate more aggressively at around 600 rpm after the car was all warmed up. I knew there had to be something wrong when my fuel economy shot down to 13 mpg. And with the gas prices going up it’s not a fun time filling up twice a week.



I decided to run some codes to see if there is anything new other than the p0430 code that’s been on my dash for over a year. And sure enough there were 2 new ones. P0174 system too lean bank 2 and p0175 system too rich bank 2.



After a lot of research I saw a lot of people say MAF sensor but I don’t believe the 06 charger has a MAF sensor. Or does it have an equivalent sensor that could cause the same issues?



After a couple days my engine started misfiring, very rarely but it was happening. I decided to replace my plugs since I have no clue when the last time was that they were done and I could scout out any other issues while I was at it. I Disassembled the intake manifold and cleaned a sensor just before the throttle body which I believe is the CAI sensor? The throttle body was VERY dirty on the inside portion (dirty as in completely black). Also it was slightly open, not sure if that’s normal my car. I cleaned the throttle body then removed the intake manifold to get to all the plugs and the 3 plugs on bank 2 were black. I’m assuming all this buildup is from the rich condition I’ve been running in. And bank 1 was completely clean, looked like new. I replaced them all anyways. I put everything together and let her run and she ran great. The next drive I took was so nice as the gas gauge wasn’t visibly going down. I thought I had fixed the issue. But a day later the codes and issues were all back. Except the misfire so far, I believe that was happening due to the plugs getting so dirty from before so it’s more than likely going to happen again eventually.



This time around I’m getting a couple more codes along with the old ones p0153 02 sensor circuit slow response bank 2 sensor 1 and p2099 post catalyst fuel trim system too rich bank 2. And now my engine is sputtering a bit during acceleration especially going uphill.



I’m at the point of so much confusion because all these codes point to so many things. Most are consistent with each code so I can’t really narrow anything down. Could be injectors, may have bad cats (I have no rotten egg smell though), possible exhaust leak (there is a small crack in the pipe right after the cat but that’s been there since I bought the car 4 years ago), could be 02 sensors idk. If anyone here has any advice you have no idea how much I would appreciate it!



Thanks for having me and reading this entire book.

 

How many miles on the car? Original O2 sensors? Does it run better if you unplug the front O2 sensors?

 

166k miles. As far as I know of yes they’re the originals unless the previous owners changed them. I have not tried unplugging them but I will and let you know the results.

 

Unplugging sensor 1 cause the rough idle to completely disappear but the car what nearly undrivable. The throttle was sometimes unresponsive with the sensor 1 unplugged.

 

On yours, if you unplug one, I think you need to unplug both front O2's, otherwise, I suspect the computer bases its fueling decisions on that one sensor, and if it's lying...... well, odd things ensue.

If your sensors are original, I would be REAL tempted to replace them. NTK or Denso sensors only though please. Bosch sensors don't seem to play well with Dodges.