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  1. #1
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    Severe hesitation when accelerating

    When I accelerate I'm getting a hesitation when about 25-30% throttle. It's the worst when I'm taking off from a stop sign. I'll take off and when I hit around 1500-2000 rpm it really bogs down until it gets up to around 2500, then it seems to go away. If I floor it, it takes off like crazy just like you would expect. I changed the plugs, cleaned the air filter, and checked the PCV valve.

    I had been getting an intermittent P0430 code so I assumed that I had a plugged CAT. I had a bad O2 sensor for quite a while that wasn't throwing a code, but resulted in a random misfire for the first 30 seconds or so after startup, so it made sense that the CAT could be plugged. I installed long tube headers and catless mids this weekend and I'm having the exact same issue. Still no codes are being thrown other than for the rear O2's. Does anyone have any suggestions as to where to look next? The car is a 2005 300c. Could it possibly be my PCM going bad? It does have the second version of PCM for '05.

    Thank you in advance for any suggestions!!

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  2. #2
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    Consider a throttle re-learn and possible MAP sensor issue?
    Have you recently done any tuning, an overly rich VE table can do this.

    Good luck.
    2013 Dodge Charger R/T Plus, Edelbrock E-Force 2300TVS 6.4 PSI, Mustang-Dyno Tuned 418hp/430tq, 3.06:1, Severe Duty Radiator, Dual Fans, OE Oil Cooler, Pursuit BR9 Brakes, Corsa CatBack, Bilstein Dampers, Catch Can, AlfaOBD enabled Sport Mode & SRT Pages, Fogs on w/High Beams, Add Reverse Cam & Auto Dimming & Tilt in Reverse Left Door Mirror.



  3. #3
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    Quote Originally Posted by gapi View Post
    Consider a throttle re-learn and possible MAP sensor issue?
    Have you recently done any tuning, an overly rich VE table can do this.

    Good luck.
    If you're talking about where turn the key on and slowly press the gas pedal, I've done that a few times. I've read mixed opinions on whether that actually does anything, I didn't notice any changes myself. No recent tuning, I've been running a canned Diablo tune for about 2.5 years. It's been doing this for about 6-8 months.

    I don't currently know anything about reading logs, if I took one and posted it here, could you or someone else have a look at it and see if there's anything out of the ordinary?



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  4. #4
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    I don't have Diablo but perhaps they can read your scans logs? Maybe foind a good Diablo forum where you can post it up?
    As for throttle relearn I use HPTuners to do mine.
    If I disconnect the throttle body connector to do work like a belt change even with the key off if I don't do a re-learn the startup is rough. Mine is a 2013. R/T.
    2013 Dodge Charger R/T Plus, Edelbrock E-Force 2300TVS 6.4 PSI, Mustang-Dyno Tuned 418hp/430tq, 3.06:1, Severe Duty Radiator, Dual Fans, OE Oil Cooler, Pursuit BR9 Brakes, Corsa CatBack, Bilstein Dampers, Catch Can, AlfaOBD enabled Sport Mode & SRT Pages, Fogs on w/High Beams, Add Reverse Cam & Auto Dimming & Tilt in Reverse Left Door Mirror.



  5. #5
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    I was just reading about the MAP sensor, I think I'll change it out tomorrow and see if that helps. For $20 it definitely can't hurt! I'll report back with the results. Thank you for the suggestion!!

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  6. #6
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    Hey, any luck with your issue?


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  7. #7
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    Quote Originally Posted by Lxreggie35 View Post
    Hey, any luck with your issue?


    Sent from my iPhone using Tapatalk
    Sorry for the late reply!

    No, still haven't figured it out. I changed the MAP sensor, and it definitely seems to run better, but no help with the hesitation. I have a feeling it might be the PCM. Right now I have a Diablosport tune stuck in it because my i1000 took a crap so before I can load any new tunes, I need to get it flashed back to stock. Hoping that when I get it reflashed it will help with the hesitation issue.

    Whenever I run it in auto stick mode, it's much less noticable because I can keep the rpms up, but as soon as I run it in auto, it's back to the horrible hesitation.

    If anyone else has any thoughts as to where to look, I'm definitely open to suggestions!! It acts like it's a fuel issue, but monitoring the fuel trims doesn't show anything out of the ordinary.

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  8. #8
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    Autostick mode also disables the MDS. Could be staying in 4 cyl mode longer than you want. Can you read your throttle position sensor percentages in the trouble zone? It could be losing the actual position in that area. Lastly, borrow a fuel pressure gauge & drive it, watch your fuel pressure to see if it drops.
    Courage is being scared to death but saddling up & riding anyway- The Duke

  9. #9
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    Quote Originally Posted by Harley's & Hemi's View Post
    Autostick mode also disables the MDS. Could be staying in 4 cyl mode longer than you want. Can you read your throttle position sensor percentages in the trouble zone? It could be losing the actual position in that area. Lastly, borrow a fuel pressure gauge & drive it, watch your fuel pressure to see if it drops.
    Forgot to mention earlier, MDS is turned off. I will definitely check the throttle position during the hesitation, thank you for that tip! I haven't checked fuel pressure yet, I will do that also, was avoiding it because I didn't want to splice into the fuel line, but I probably should just do it so I know.

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  10. #10
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    Sounds good. Keep us posted...
    Courage is being scared to death but saddling up & riding anyway- The Duke

  11. #11
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    I took a ride to the Friday night drags and on my way I monitored the throttle percentage with the Torque app, and it definitely appears that at the same time I'm experiencing the hesitation, the throttle percentage is dipping even though I have my foot in the gas. It even appeared at one time to be bouncing slightly erratically a few percent while accelerating.

    Any ideas on what could be causing this? Bad throttle body or TPS? I cleaned the throttle body maybe 15k miles ago when I first noticed the problem and it didn't seem to help at all then.

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  12. #12
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    Most likely TPS but I'm not sure where it is on yours.
    Courage is being scared to death but saddling up & riding anyway- The Duke

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