My Question:
How do I remove the check engine light?
My Innotech 3100 OBD II Code Reader gets an error signal every time it reads my Dakota.
Though it works on all other 5 models of vehicles in my household.
This same reader diagnosed my truck 2 years earlier in 2013.
I own a Dodge Dakota SLT 2007 V6 3.5L King Cab.
My check engine light comes on and off throughout its lifetime.
In 2013, I had a reading of p0303. Which indicates a 3rd cylinder misfiring.
I corrected that problem, however, since then the check engine light continues to reappear at times, and disappear for no reason at all, also for equal amounts of time.
Now as I try to pass SMOG this year, my emissions are great from being tested, but the check engine light is causing me not to get my SMOG certificate.

 

I moved your post to the 3rd gen forum.

 

Try another reader just to eliminate that as the problem. Most auto parts stores will do this for free.

 

Thanks. In California they're telling me that its illegal for them to do so. And said to buy another. Will ask a buddy if they got one before buying another

 

sounds like a partially clogged catalytic converter. When you had the misfire, the cat on the side of the misfire started to clog up and the O2 sensor is most likely dirty as well, causing the intermittent check engine light.

buy the aerosol Seafoam and do the spray treatment from the front of the throttle body. The liquid one that you do using a vacuum line is too much work if you ask me but if you pick the correct line, it's just as good. This should clean up the cat for you, and at the same time, clean the throttle body, intake manifolds, the top of the valves, the cylinder walls, the top of the pistons, the exhaust manifolds and some of the rest of the exhaust.

Made a huge difference for me after my misfire incident i was getting. Even with new plugs and coils, i had a random misfire that kept occurring that was caused by a clogged cat, too much exhaust pressure on the driver's side exhaust causing spent exhaust to be re compressed. after the seafoam, the truck breathed better then when i got it.

 

Thanks will give it a try

 

I actually went through something very similar after dealing with a misfire that just wouldn’t fully go away. Even after changing plugs and coils, the check engine light kept coming back randomly, and the truck felt like it was struggling to breathe. It turned out the misfire had caused extra stress on one side of the exhaust, and the catalytic converter was starting to clog, which also affected the O2 sensor readings. After addressing that, the engine response noticeably improved and the exhaust felt less restricted. While sorting everything out, I was also double-checking factory specs and options using https://carfast.express/en/window_sticker/ram with a ram vin window sticker, just to make sure nothing else was overlooked. Once everything was cleaned up and flowing properly again, the truck honestly felt smoother and stronger than it had in a long time.

 

When we had that emissions test an I had p0300 a seafoam spray clean up thru the brake booster really helped clear it up,an new PCV ..an I used seafoam thru the fuel too,an new plugs finally got it into ready mode ,after so many runs, for it to pass ..a plugged cat can cause that too though.
Does yours have the 3 key turn CEL error code option? That holds onto pending codes ,even before some of the best readers/scanners get the code..I was testing mine an it had just became a new pending code ,shown by the 3 key turn ,but not set yet for OBD2 scanner nor ELM32 plug in testers..


Try that clean out .an reset/ retest .!