P0342 code & Fuel gauge not working!

[jb3golf]

Hey guys here's my problems and background:

1. I have an LS1 forged block with afr heads and full bolt ons.
2. About a week after installing the Spinmonster cam (230/234 @ .598, 613 on 114)..my car becomes hard to start. Starts stumbling and at times shutting down at idle...at first there were zero codes...so I checked my fuel pump..all good..then when I unplug maf sensor..the car idles fine!? Then later on it throws P0342 Dtc...I read up and see it could be cam bolts backing out...pull water pump and separate 2 piece cover, only to find all bolts are perfectly tourqued as I had left them...then I double check pcm and all checks out..then I see an open insulator section near cam position sensor...I purchased a connector wire and solder all the wires correctly. ..car still does the same thing. ..then I install new ac delco cam position sensor. ..still the same thing...code is P0342 low circuit b....I'm stumped guys on this one....

[jb3golf]

Am I missing something? The comp cams box stated the cam was for LS1/LS2/LS3/LS6..just as the website portrayed. . Does the Spinmonster cam possibly have a front mount cam sensor trigger on it? The cam was a common 3 bolt design...How else would this code set? I haven't located a short anywhere but will keep looking...and if it was an issue with the cam, how come it idkes just fine in SD mode when the maf is unplugged?

[SMWS6TA]

It's most likely you need to get it tune for the cam. I have to do the same thing in order to get mine to start on a break in tune with my cam setup. I have other issue but even with the modest cam you have it will still need to be tune.


You can run it with the MAF unplug, this will put the ecm into speed density mode and will keep the popping a code until it is tuned to run with the MAF or as a Speed Density Tune.

Average cost is about $500 for a full tuning session.

[jb3golf]

It's most likely you need to get it tune for the cam. I have to do the same thing in order to get mine to start on a break in tune with my cam setup. I have other issue but even with the modest cam you have it will still need to be tune.


You can run it with the MAF unplug, this will put the ecm into speed density mode and will keep the popping a code until it is tuned to run with the MAF or as a Speed Density Tune.

Average cost is about $500 for a full tuning session.

Ok. Thanks for the info...However the car was already tuned for a cam I had in there before..and the car ran just fine before these issued came up (with spinmonster cam already installed)...additionally, i don't see how a few adjustments on the current tune would cause a P0342 code to just disappear. ..A short in the circuit I would think has nothing to do with what cam is installed If i am thinking correctly. ..also the car runs fine ONCE the computer goes into closed loop. ..i think that should be a clue? So, once the computer switches to O2 sensor readings it drives normal and with full power....i will keep searching. ...also my oil pressure is spot on so I don't think the cam thrust bolts are in issue. ...any other ideas?

[jb3golf]

Also why would my gas gauge be non functional? I'm thinking maybe an electrical short somewhere? I'll post feedback as I continue to eliminate each possible culprit....

[SMWS6TA]

when you did the install did you do in or out the car?

[jb3golf]

when you did the install did you do in or out the car?

All work was done inside of car....However i think I figured out my problem! I Decided to Look More INTO the wire loom covers to see if I could find any broken wires....low and behold there is the cam position sensor brown/white wire completely severed and just barely holding on by a strand....it appeared someone had tried to fix this issue prior to my ownership. ..and they did a horrible job..wires weren't properly adjoined..and no there was no soldering present....i bridged the two with new wiring and soldered them for an unbreakable seal....since I'm working i can't actually start it until later tonight or tomorrow. ..we shall see....thanks

[jb3golf]

So...i ended up purcasing and installing a new ac delco cam position sensor, a new pigtail connector (installed)..installed a new 800 horsepower capable fuel pump, removed the water pump/cover to check cam bolts (perfect)..removed intake twice to install sensor etc...only to find the broken cps wire severed on the wire loom section.....OH WELL. ...lol...I'll check back tomorrow to confirm if this was the issue. ..

[jb3golf]

Orion..where you at? You usually help me out with my issues!!lol.... Glad to see you are still apart of the site...

[pajeff02]

Subscribed to see if the problem is solved.

[SMWS6TA]

electrical gremlins are always a PITA to fine. Hope this fixes it . Usually that happens when ppl are pulling/installing motors.

[jb3golf]

electrical gremlins are always a PITA to fine. Hope this fixes it . Usually that happens when ppl are pulling/installing motors.

Right...you guys are 100% correct...the funny thing is how we all sometimes don't find the issue until money is spent and labor is performed. ..but at least most of us on this site have the guts to figure it out ourselves instead of getting ripped off at the stealership and/or automotive shop...i stilll see it as money saved....I'll update shortly...As I will be attempting to start it soon...

[jb3golf]

Ok guys...here's my update step by step: After repairing brown cps signal wire, the car started, but eventually started acting up again with erratic idling and the car feels like it wants to die and is searching for proper air fuel ratio. ...So..i figured I must have ANOTHER short somewhere. ..i look over my wiring and discover my alternator wire is full of gue (looks like brown glue?!) And this gue actually leaked all the way into the pigtail harness!....i had an extra wire lying around so I soldered the new pigtail connector alt wire...go to start it...and STILL the same issues AT idle....well I refuse to give up so I keep searching. ...meanwhile my car is just stumbling miserably as I keep hoping it settles down...Then as I have it idling. ..it just dies on me (I'm in my carport area just outside the garage btw) I turn the key over, and ZERO priming of the pump! I mean it completely stopped working....So, i get started on that job...i discovered that both of the signal wires ( black and gray) that connect to the high performance pump have exposed wires...NOT good in a fuel tank! Lol....So, i happened to have a new pump in the garage so I figure I would see if this was a fluke and changed it out....sure enough the new pump (albeit oem) primes right up with no issues. ..i then go to start the car and it catches, BUT it still stumbles and still can't establish a good idle....i decide to disconnect the MAF sensor plug....AND all of a sudden the car runs and idles perfect! So I stop to take a couple of mental notes: Ever since I fixed the cam position sensor brown wire the car NEVER threw the P0342 code again..which is good...i replaced and strengthened the alternator wire and harness...which is good...I replaced my failing (due to wiring) fuel pump with a new one. ..A good thing....

Then I take the F-body out for a 15 mile drive...ALL is spot on and it drives great with zero issues (maf of course is still unplugged)...it acts like there are all of a sudden no issues or electrical shorts.....i don't quite understand exactly WHAT is going on but I am worn out from this excursion! Also my fuel gauge never came back to life...still a dead, limp needle on "E"...lol....

[jb3golf]

Im still optimistic but don't understand how unplugging the MAF can calm things down so drastically....and i don't get how the fuel gauge tach just failed and never returned to life. ...this is not over and I'm thinking maybe I should switch to a speed density tune and call it a day...does anyone have any advice for me? ANYONE?

[pajeff02]

If the MAF is misreporting airflow it throws everything off as the amount of air actually entering the engine is different than what the PCM is being told. When you unplug the MAF, it forces the PCM to estimate airflow based upon manifold air pressure, r.p.m., and such which gets it closer than the messed up MAF did. Since you had a wiring issue, it is possible something shorted so check your <ENG SENS> fuse before you go making drastic changes. You can also borrow a known good MAF from a friend to see if that solves the issue.

[jb3golf]

the MAF is misreporting airflow it throws everything off as the amount of air actually entering the engine is different than what the PCM is being told. When you unplug the MAF, it forces the PCM to estimate airflow based upon manifold air pressure, r.p.m., and such which gets it closer than the messed up MAF did. Since you had a wiring issue, it is possible something shorted so check your <ENG SENS> fuse before you go making drastic changes. You can also borrow a known good MAF from a friend to see if that solves the issue.

Good advice pajeff02....you are absolutely correct here....After further review and educating myself about this specific scenario, the only logical conclusion is that the MAF had to have suddenly failed, and can't determine the actual airflow that's entering vs the predetermined value based off the prior tune....

The good news is that several unknown issues were addressed through this process so i am very thankful for that. ...i mean many of these issues I have disclosed in this thread could have resulted in all kinds of REAL trouble HAD I been driving somewhere. ....I also ascertained what I already knew; that my tuner did a wonderful job tuning my vehicle, IN THAT a speed density tune was part of my street tune, just in case my maf failed. ..most of his tuning was with the Maf unplugged, so the car is spot on and I'm good to go until I can get back to him for a follow up...I'm also pleased that the P0342 code was solved via that severed cam position sensor brown wire located in the wire loom near the pcm...all in all the process has been very involved BUT I have learned a ton and at least eliminated that whole "cam bolts loose" scenario. .I think that was my main concern in terms of worse case scenario circumstances. ...I also think (and to mimic your wonderful advice above) that researching the closed loop/open loop operations of our vehicles helped me to understand clearly WHAT has been going on regarding the Maf's behavior and it's function in open loop mode.......my objective conclusion is that multiple things were failing/going on at the same time in which were hard to properly diagnose...There are so many symptoms that are vehicles exhibit that could be a result of 20 different issues that may not reveal themselves through DTC notification. ..

Thanks again for your assistance and i will update this thread down the road when I ultimately get a retune.....

[jb3golf]

Additionally, i checked the engine sensor fuses and all other fuses a while back to no avail....and my fuel gauge is still stuck on empty. ..it's VERY possible the car is simply showing it's age.....maybe a newer 99-02 pcm is in the future....