Where is the leak detection pum on a 1997 dodge 3500? any advise on reparing this problem? Adam

 

It's usually located under the battery and power distribution box area. A lot of times code 1495 will pop up when the LDP solenoid or it's circuitgoes bad and code 1494 pops up when there is a mechanical problem with the LDP.

 

if the 1494 code pop up does this mean that the LDP needs to be replaced.

 

9 out of 10 times, yes.

 

i checked and everything and also cleared the codes. I drove it for 60 miles and i got the 0420 code? do i still need to replace the LDP

 

Here is an article I found from

http://www.obd-codes.com/p0420

You will likely not notice any drivability problems, although there may be symptoms.

Causes:
A code P0420 may mean that one or more of the following has happened:

Leaded fuel was used where unleaded was called for,
An oxygen sensor is not reading (functioning) properly,
The engine coolant temperature sensor is not working properly,
Damaged or leaking exhaust manifold / catalytic converter / exhaust pipe,
Retarded spark timing
The oxygen sensors in front and behind the converter are reporting too similar of readings.

Possible Solutions:
Some suggested steps for troubleshooting a P0420 code include:

Check for exhaust leaks at the manifold, pipes, catalytic converter. Repair as required.
Use a scope to diagnose the oxygen sensor operation (Tip: The oxygen sensor in front of the catalytic converter normally has a fluctuating waveform. The waveform of the sensor behind the converter should be more steady).
Inspect the downstream heated oxygen sensor (HO2), replace if necessary.
Replace the catalytic converter.
One thing to note is that many vehicle manufacturers offer a longer warranty on emissions-related parts. So if you have a newer car but it's out of it's bumper-to-bumper warranty, there still may be warranty on this type of problem. Many manufacturers give a five year, unlimited mileage warranty on these items. It's worth checking into.

 

how can i check to make sure the timing is correct? Does anyone have a spark plug wire diagram so i can make sure the wires are set correctly?

Okay well i cleared the codes again. I want to see which ones I get a second time so i can replace them and i got the 1494 so i will be replacing the LDP on tuesday. Know the wierdest thing happend twice the D stalled which thats normal by now but when i went to restart it it started back up but with a really low RPM and i could here a type of knocking sound then the D turned off by itself and what seems to be the exhaust smoke came out of the intake filter? would a clogged cat do this?

 

There should not be any exhaust smoke coming from the aircleaner. I do not believe that the Vapor Cansister Leak Detection Pump will cause this. A clogged cat, improper spark timing, would do as you described. Improper cam to crank timing (jumped chain), and improper spark plug wire firing sequence will cause the engine to run with a missfire at all times. With the previous P0420 I would have a serious look at the cat.

Firing order is 1-8-4-3-6-5-7-2. The rotation is clockwise. The timing is controled by the PCM. The timing is not adjustable. Do not move the distibuter. If you have moved the distibuter then it will need to be resynchronized with the fuel system.

 

thats how my spark plug wires are connected, i dont notice a missfire as the D runs good when it wants too...ill be replacing the Cat hopefully tomorow but they are expensive the muffler quoted me at 280 installed....i belive my PCM is also bad as the D stalls all the time with no warning

 

okay guys i changed the LDP and that made no difference. I went ahead and replaced the catalytic converter. The D still Stall alot. Seems to be backfiring and the D has no power at all. I will be replacing the PCM see if that the problem