Over time my Dak was getting harder to start. Finally one morning it wouldnt start. I have P0351, P0123, P0152 for OBD codes.
I am getting spark and fuel so I think the O2 sensor has plugged up the Catalytic converter. Soo..I climb under and cut the cat out and move it to the side. After a few tries, the Dak started, but wouldnt rev if I stomped it, but would rev if I gradully gave it throttle but it backfires horribly. So I call the Dodge house and tell him I need a main cat and the 2 pre-cats that are attached to each exhaust manifold. He says there is only ONE MAIN cat and no pre-cats on exhaust manifold. WTF?! I see them with my own two eyes! They also have O2 sensors in them. Both sides have 1sensor.
OK, what would happen if I just took the 2 pre-cats out and just ran with the main cat?
Do any of you guys with 5.9L Daks have a main cat and 2 pre-cats, one on each exhaust manifold?
What harm can be had from installing A-zone cat for now with no pre-cats? Needing help guys/gals. Military doesnt pay well enough for me to install all new exhaust at Dodge house....$899.99 just for main CAT...ouch.[]

 

P0123 (M) Throttle Position Sensor Voltage High Throttle position sensor input above the maximum acceptable voltage.
P0123 (M) Accelerator Position Sensor (APPS) Signal Voltage Too High APPS voltage input above the maximum acceptable voltage.

P0351 (M) Ignition Coil #1 Primary Circuit Peak Primary circuit current not achieved with maximum dwell time.

P0152 (M) 2/1 O2 Sensor Shorted To Voltage Oxygen sensor input voltage sustained above normal operating range.

From what it sounds like by the codes being thrown, I wouldn't waste your money on new cats yet. I would try cleaning out the named O2 sensor above and replace your Throttle Position Sensor (TPS).

 

OOPS. already cut out the main cat and hacked it up pretty good getting it out.
what will happen if I run it w/o the cat and the o2 sensors in it?

 

your 02's are gonna throw a CEL

 

and it'll run like ****. put them back in. I've had the same problem with dodge on the pre-cat issue with my 2000 ram, same setup as yours, they calim it doesnt have 2 cats. from what your describing I'd yank the battery terminal and reset the pcm, then get a fresh set of codes. then let us know what they are.

 

Permanent MIl for downstream O2's.

The P0152 code indicates that your right upstream 02 heater circuit and output circiut have crossed. Check the wiring for that sensor, and if OK, replace the sensor.

P0123 is most likely a bad TPS (could be reference and signal wires rubbed through on each other)

P0351; either the coil is failing, or it's not getting full voltage to charge. Coil primary resistance should be .6-.9 ohms. If that checks out, make sure it is supplied with battery voltage (account for wire resistance; for example, 12.64 battery volts and 12.49 volts at the coil is ok). If supply voltage is low, it's either the connector, wiring or ASD relay contacts. Start by just unplugging and reconnecting the coil and removing and the reinstalling the ASD relay. Electrolytic corrosion of terminals can increase resistance, thereby lowering voltage. Usually just upsetting the connection will re-establish good contact.

 

was told coil code was because of MSD box. told that by MSD.

 

Steve, The codes posted ARE the new ones. I dont know what to do. I removed the main cat and now it starts but wont rev when I stomp it, only revs when I gradully increase throttle.....WTF?
Pre-cats are bad I know ones plugged but, Dodge wont order them cuz he says they dont exist...what now?

 

gutted cats, installed a flowmaster, rplaced tps, and cleaned iac. still hard to start. got fuel pressure....how do I check for bleed down of fuel pressure? I think I have an injector leakin....

anyone?

 

put a fuel pressure gauge on the rail, turn the key on and see what pressure you have. if it is 49 psi on the 1st key turn, then your drianback check valve should be fine. it should hold the 49 psi for a few minutes (forget exactly how long, download the manual and have a look at it to see what it says). if you do have the 49 psi and it holds, then have someone fire it up and see if the pressure is holding its spec of +/- 5psi.

are you still getting the tps voltage code? did you check the voltage out of the tps yet? should be 5v, signal & gnd... the signal has been reported to be anywheres between .5 & .9 v IIRC... .7~.75 is ideal and is recommended for the best performance. If you do suspect the TPS still, and are going to change it, give cleaning it a try. I just did this myself on a 4.7 TPS and it worked great. the link to what I did is in the DIY thread @ the top. that would at least eliminate something funky going on with it.