hi everyone ... i finally got my internet serv. back on yay ! back to my problem , i finally fixed the leak and put new gov press. sensor , lock up switch on my 99 ram 15004x4 .... ran fine for like a month .... now its acting kinda funny ??? when i its cold it drives fine but when it reaches operating temp it starts lagging on power , it also floats around the 2k rpm range when it gets warm and top speed is 60-65mph , 4th gear wont engage unless its been driven for 30+min.... i looked through the forums and suspected a clogged catalytic conv. but went to my buddy's shop and cut it open and its already been gutted...there is no check engine light on either... im suspecting its the fuel pressure but i installed a new pump 2yrs ago , but i left it parked for a 1yr and 1/2 with a 1/4 tank with no fuel stabilizer .. could that of damaged it ... ima do a fuel pressure test tomorrow to see if its the pump .. i think im going in the right direction with gas pump , but im open to any ideas or solutions thanks everyone !

 

It may be your o2 sensors as well don't rule them out.

 

wait a minute ?! the o2 sensors can go bad without the engine light going on ? would that put it in a sluggish state after warm up ?

 

Yep. Shore would. The computer doesn't start paying attention to them until the engine warms up..... What you are seeing is a classic sign of an O2 sensor on its way out.

Welcome to DF!

 

Try replacing just the front sensor, the one in the catalytic converter (if you left it at the stock, factory location after you cut the cat up). Thats the one that helps the PCM control your air-to-fuel ratio. The rear unit, after the cat, just detects if the converter is bad or not. Or at least, thats what its supposed to do.

 

i finally checked the fuel pressure on my truck.... when its cold it has a reading of 45psi with the key on and running about 44psi ... on my repair manual it states that it should be between 35-45 psi..... but since it only gets sluggish when its at reg operating temp ... so i tested it after driving for 20min. the readings were at key on it would shoot to 50psi then would drop to 35psi within 5-10 sec and will stay at 35psi . when i turn the truck on , the needle moves erratically between 48psi and 53psi .... is that normal ? another thing i noticed was when i put in D it drives sluggish but if i manually shift it from 1-D it revs up fine and wont stick at 2-3k rpm .... would the gov. press, sensor do that or lock up switch ... and i just put those those two sensors on less than 3months ago ? if it was the pre-cat sensor can i unplug it and see if that makes a difference since a forum member mention that an 02 sensor can make it sluggish ?

 

Not sure that unplugging the O2 will help you. If the PCM doesn't see a signal from the sensor, it will continue to run in open loop. You can try it, and see how it does...... won't hurt anything. (just make sure to secure the harness out harms way. )

 

Your fuel pressure is good and dandy...so you can cross that off...I think more than likely you have a bad sensor somewhere. Probably bad O2 sensors as the other guys have mentioned...Also a possibility of bad IAC or TPS sensor on the throttle body? hmmm.....At least pull these out and clean 'em, make sure they look safe and sound anyways. (Suppose to clean these once in a while anyways) Its quick and very easy to do this. Only two screws per sensor, and a good place to start (FREE).

 

i was already dreading to buy another fuel pump lol... i'll check the tps and idle air valve next .. thanks guys for the info i'll post again after check the two !