Hi im the owner of a dodge dakota 2003 dual cab 3.7l v6, aroudn 210k miles. From 4-5 days ago when i turn it on as long is idle is fine but as soon as i press gas it starts missfiring, after 2krpm it goes crazy between 2k and 4k, then if let idle it kind of wants to turn off but doesn't, now it does this as long i dont run it, if i take it for a stroll after a few blocks when engine is warm starts working fine, then let it sit for a few hours and same problem arises. Took it to local autoshop and computer throw these codes P1281 P0340 P0133 P1391, since one is the camshaft after doing some research found the camshaft sensor been a disc inside the distributor (can be wrong just googled it), replacing it did nothing so i have a friend claims i need to replace the crankshaft too but no idea in what part of the engine is this sensor, maybe someone here have an idea or same engine and can help me figure it out where it is so i can replace it, thank you for any help.

 

Welcome to the forum.

The P0340 and P1391 are likely related. I'd also suspect the cam sensor since that's the common point. Yes, it is in the distributor on your 3.9, it's not a 3.7 in '03. It may be the cam sensor too.

P1281 could be the thermostat.
P0133 a bad O2 sensor, don't use a Bosch replacement.

 

thank you for the welcome 00DakDan, really appreciate the input on the problems, i did figured the camshaft using a google image (which thank you for verifying is the one on the distributor) but for my life cant figure where the crank sensor is,this is my first time dealing with a car problem myself hence i thought was 3.7 not 3.9 lol. So im guessing the best approach would be replacing the 3 sensors and the thermostat ??

im guessing this is the image i should be following correct?

 

Yes that's the crank position sensor CKP.

What brand cam position sensor (CMP) did you use?

While they may be more expenisive than aftermarket, OEM is the way to go on sensors. Lots of aftermarket parts just never work quite right.

 

I can also tell you from experience, don't use the cheap china made sensors like BWD, they have very weak magnets, they wont trigger properly..