Hi everyone. I have a 2001 Dodge Ram 1500 5.2l 4x4 and the truck has been acting poorly lately with rough idle and acceleration hesitation. However, I have noticed the truck accelerates best when the engine is cold and sometimes the motor takes a really long time to get to operating temp and other times it heats up quick... The CEL does not ever come on even when I first turn the key to the on position and I've been told that it should so I think the bulb is blown since all other cluster indicators come on.

Anyways, I took it to a local auto parts store to have the codes ran since it has been running poorly. Codes 22 and 72 came up but I have no idea what they are and neither did the guy that ran the scanner. Does anyone know what they are and if they could be possible problems causing the engine to act funny?

I really appreciate any input

 

Scanner should come up with P codes.... P####.....

In any event:

22: Engine Coolant temperature sensor input out of normal range.

That would explain the engine running poorly.

72: Cat failure. Your cat has failed.... (at catching mice? )

Coolant temp sensor is right smack in the middle, at the front of the engine, just to the drivers side of the thermostat housing. The sensor tells the pcm what temp it thinks the engine is, and in turn, the pcm suggests to the dash what temp it should tell YOU the engine is. If the sensor is lying, the engine simply will not run good.

Your cat has probably melted down....... and is in need of replacement. Of course, before replacing it, you should fix the REASON it melted in the first place. The temp sensor.

Welcome to DF!

 

What heyyou said. . . replace the sensor and see if its running better. Worry about the cat afterwords. If you don't have emissions testing you can just gut it. If you do have emissions id suggest a high flow as they're a lot less expensive than the oem and flow much better.

 

Thank you guys very much for responding. That makes perfect sense. My temp gauge sometimes stays cold even after driving 30+ min. I'm going to test the harness and the sensor today. I have a multimeter And btw, my truck does not have a cat so... lol. Previous owner cut it off and straight piped it. I've heard that pcm for newer Rams are sensitive to not having a cat. Is that true? Will it effect performance?

 

You could have a bad plenum gasket also. You need a O2 fix for your 2nd O2 sensor http://bigdaddiesgarage.com I'd buy a new sensor when you do this.

 

So guys. I was searching online to see exactly where the Coolant Temp Sensor is and some guys are saying it's under the alternator next to the thermostat housing which if true for me then that sucks lol. Then I heard that there are two different CTS's. One is for the gauge which I think I found (I will post a pic of which one I think it is) and the one for the PCM is the more difficult one near the thermo housing. My guess is I need to do the one for the gauge but idk... Any of you guys have any idea?

 

 

There's also the spark plug non-fouler trick.

 

Your picture is of the intake air temp sensor. It's not the one you're having troubles with.

Take your airfilter housing off and look down right behind the AC compressor towards the radiator hose side. You will see a little sensor with 2 wires. That's your engine temp sensor.

97 ish and older trucks have 2 temp sensors, one for the gauge and one for the computer. 98 and newer only have the single sensor.

 

Thank you for the reply Frankie. Hopefully I can get to it just by taking off the air filter and the radiator hose. I will post again once I test the harness and replace the sensor and see the results.