Check engine light after PI intake/cam install (long)

Discussion in '96-04 - 2V Specific' started by Olstangguy, Apr 14, 2007.

  1. Olstangguy

    Olstangguy New Member

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    Need help with CEL and PCM issues 98 GT 91,000 miles on the odometer. These are basically notes to myself:
    Would like your comments/suggestions. Check engine light comes on after 20 minutes of driving after reconnecting battery.
    Rough running at Idle and at cruise speeds (closed loop) Codes: P0172 Bank 1 Rich - Passenger (Right)
    P0174 Bank 2 Lean - Drivers Side (left)
    The main thing I’m going to do right now is to drive it carefully for a few more complete cycles in hopes that the PCM will adapt
    to the new air flow. Will NOT be disconnecting battery to reset computer.
    What I’ve done so far or intend to do:
    Listen carefully for detonation. Result: NO DETONATION DISCERNABLE.
    Determine if it runs OK in open loop Idles OK ?? throttle response ok ?? result: SEEMS TO RUN OK IN OPEN LOOP
    2 Possible vacuum air leak left side causing computer to throw left bank lean code and enrich mixture thereby making right
    bank throw rich code,. Check for vacuum leaks especially around left side of intake manifold, injectors. - doubtful because I’m pretty
    sure it was installed correctly. Spray some carb cleaner around potential vacuum leak areas. Result: NO DISCERNABLE LEAKS
    3 Clean the MAF with contact cleaner. Possible but unlikely. DO THIS SOON
    4 Check temp sensor, the one that sends data to the pcm – probe voltage Remove the Teflon thread wrap from sensor threads.
    5 Check air temp sensor in the CAI – disconnect it – probe voltage - doubtful
    6 Take out the 180 degree thermostat and replace with stock one. Doubtful.
    7 Remove the IAC restrictor. Doubtful since it runs rough under power. Result: NO EFFECT OTHER THAN GETTING THE RPM HANG BACK.
    8 Swap the right and left O2 sensors. See if lean/rich codes switch from left to right. DO THIS AFTER I DRIVE IT FOR A FEW MORE COMPLETE CYCLES
    9 Replace both 02 sensors ? Doubtful, to much of a coincidence for one to go bad just now. No code indicating bad o2. they seem to be working.
    10 Drive it easy for a few more complete cycles. See if the PCM adapts.
    11 Intake manifold installed wrong ? I don’t think so. Pull it off and install it again ? LAST RESORT
    12 One or both of the cams installed out of time ? Don’t think so. Very doubtful. How would that throw rich/lean codes anyway ?
    Pull cover and chains, check cam timing. VERY LAST RESORT
    I know I'm probably making a big deal out of nothing, but i didn't expect the CEL or crappy running after the intake/cam swap.
    Any thoughts or suggestions would be great. I know there is a lot of knowledge on this subject out there. Thanks guys.
     
  2. AUTOBAHN

    AUTOBAHN Member

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    You need to really check out your work. I just did my cams today(already did the intake earlier). No codes at all, and it runs smooth. My car is a 97 GT. The only thing that sounded odd was when I first fired it up there was a clattering sound for only 5 seconds as the adjusters refilled with oil.
    Mike

    P.S. I hope you get it worked out soon.
     
  3. DropTopPony

    DropTopPony Administrator Staff Member Admin SN95 Supporter

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    check and re-check the hoses/vacuum lines etc...i hope it was something simple and works out for you.
     
  4. Olstangguy

    Olstangguy New Member

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    Its running quite a bit better tonight. Check engine light is still on. made no effort to turn it with off a scanner yet. Idle hot is about 600 rpm. Tomorrow I'll clean the MAF sensor, cancel the CEL and see what happens The more i think about it the more i think it could be an O2 sensor. I know the right one was drenched pretty good with PB blaster just before I did the intake / cam work. I'm probably way overreacting to this problem. I put a new or H pipe on and of course it sounds a lot different which could lead me to believe its running rough when its not really that bad. Think I'll have a double manhatten and go at it tomorrow. and yes, will double check everything.
     
  5. voidfinger

    voidfinger Well-Known Member

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    lol you put a O/R H on it....and you asking why its throwing a CEL? Do you have MIL Elimiators on or not? if not then thats your problem.

    Hope its that simple but lol sorry but lol
     
  6. Olstangguy

    Olstangguy New Member

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    MEL eliminators, yep I have them. Thanks for the advise. Wish it were that simple. Codes are P0172 Bank 1 Rich P0174 Bank 2 Lean
    I still have to check the O2's by swapping left for right
     
  7. 97blackgt

    97blackgt Well-Known Member

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    exhaust leak?
     
  8. Dalamar

    Dalamar Legend Retired Staff SN95 Supporter

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    could it just be the normal remap?
     
  9. DropTopPony

    DropTopPony Administrator Staff Member Admin SN95 Supporter

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    Has it got any better with time?
     
  10. nyuk98gt

    nyuk98gt Member

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    Olstangguy:

    O2 sensors are not very tolerant to coolant. If some dribbled into the exhaust when the old intake was removed (or some other way), the sensor(s) may be wounded. I don't know about PB Blaster but it ought to burn off after a while. The 'swap the O2 sensors from one side to the other' suggestion will help to identify if the sensors are wrong or if there is a leak on the lean side.

    Keep us updated, please.

    Chris
     
  11. Olstangguy

    Olstangguy New Member

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    O2s were replaced Saturday. No improvements. Codes P0172 and P0174 – right bank rich – left lean.
    Next week, going to check the cam timing. Regrettably, and against good advise, I used the Andersen cam tool method for my cam swap.
    So now I have to do it again to get it right. Lesson learned Hope I can find a crank pulley puller.
    Oh one question – Is it necessary to use a new crank bolt ?
     
  12. nyuk98gt

    nyuk98gt Member

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    Olstangguy:

    Yes, you need a new crank bolt. It is a torque to yield (TTY) and MUST NOT be re-used. You can get an ARP bolt from Summit and re-use it like there's no tomorrow.

    FWIW, I used the Anderson tool but I pulled the front cover to confirm timing -- it was perfectly fine. I think the tool (actually, the Ford version) works just fine. You need to lock it in place with a slight turn of the crank and have a buddy hold it steady while you swap the cam.

    If you have the tools, you should degree the cams to confirm true timing. There is a fair amount of slop in the gears (the keyway is big and allows +/-4 to 6 degrees) so you may not have optimum power by just following the standard cam timing routine. Kinda explains why some cars are "factory freaks" -- the cams are timed correctly -- just by luck.

    A couple manhattans, eh? :thumb:

    Chris
     
  13. voidfinger

    voidfinger Well-Known Member

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    the balancer bolt is Torque to yeald, so it needs to be replaced
     
  14. Adam

    Adam Member

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    The crank bolt can be re-used once. It is TTY but not like the head bolts. I re-used mine 3 times and my car got beat on like nobodies business. If you have one handy then yes I would put it on. I wouldn't let it keep you from finishing thr project though.
     
  15. nyuk98gt

    nyuk98gt Member

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    OK, Adam, I bow to your experience. :thumb: Being a big chicken, I got an ARP bolt and don't have to fiddle with the TTY torquing procedure.

    Chris
     
  16. Adam

    Adam Member

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    No I am not saying its the RIGHT thing to do. If you were smart enough to plan ahead and order one then by all means use it. I just meant if that bolt was holding him up, then re-use it. ;)

    Adam