Ported intake manifold and t body PO121
Ported intake manifold and t body PO121 I had my intake manifold and throttle body ported and now I am getting a PO121 code. Anybody else who had them ported get the same problem? Problem is that it is affecting shifting and also the throttle is touchy on the car. Any solutions, besides throwing a stock tbody back on it which defeats my purpose?
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From: CT
FWIW, ported TB's don't really do much on these cars anyway... not worth it IMO.
didn't know you were having those issues - on the DS forums you just mentioned that you were getting the code...
check the items neilownz suggested, as the tune I sent you only has the code disabled so you don't get the CEL anymore...
there is no setting in the tune for the minMAP / maxMAP as you mentioned you read in other forums... so you will probably still have those shifting issues...
the touchy throttle is the whole point of a ported TB - that's about the only thing it does for ya on our cars, is to give you better/quicker throttle reponse...
didn't know you were having those issues - on the DS forums you just mentioned that you were getting the code...
check the items neilownz suggested, as the tune I sent you only has the code disabled so you don't get the CEL anymore...
there is no setting in the tune for the minMAP / maxMAP as you mentioned you read in other forums... so you will probably still have those shifting issues...
the touchy throttle is the whole point of a ported TB - that's about the only thing it does for ya on our cars, is to give you better/quicker throttle reponse...
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06MonteSS / DiabLew Tune
2014 Camaro 2SS/RS - LS3, 6-speed manual, short-throw performance shifter, NPP dual-mode performance exhaust, 1LE front splitter, ZL1 rockers, Z28 Rear Spoiler, all paint-matched Red Rock Metallic, BMR strut tower brace, Cold Air Inductions cold air intake, Apex Motorsports, Inc. catch-can, Custom DiabLew Tune
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com
06MonteSS / DiabLew Tune
2014 Camaro 2SS/RS - LS3, 6-speed manual, short-throw performance shifter, NPP dual-mode performance exhaust, 1LE front splitter, ZL1 rockers, Z28 Rear Spoiler, all paint-matched Red Rock Metallic, BMR strut tower brace, Cold Air Inductions cold air intake, Apex Motorsports, Inc. catch-can, Custom DiabLew Tune
www.diablewtune.com -- www.diablocustomtune.com -- www.diablocustomtunegm.com
Last edited by 06MonteSS; Sep 6, 2008 at 10:57 AM.
The ported tbody was part of the deal with the intake manifold porting, so it was done as a package. So far as the check points from Neil that were taken from the LS1 boards more than likely refer to a cable based throttle body, while ours is drive by wire:
Idle screw might not be set right. (We have no adjustment)
Throttle bump stop could have been modified. (Probably)
Try doing an IAC(TPS) relearn. (I believe the car checks this when the key is in the run position, no difference)
TPS sensor. (Can't buy just a sensor, need to buy whole T-body)
I put on a new t-body and I regained my shift points, proper shifting and control of throttle. Yes a ported throttle body does increase response, but in this case it is throwing off a few settings the ecm looks for. Car would even stumble under acceleration because of it. The throttle body/drive by wire system controls quite a bit based on its calculations/proper range.
We need to figure how to tune around it, I'll be putting the ported unit back on and seeing what happens with the tune you wrote me that disables the code in the next day or two. Thanks again for your help!
Idle screw might not be set right. (We have no adjustment)
Throttle bump stop could have been modified. (Probably)
Try doing an IAC(TPS) relearn. (I believe the car checks this when the key is in the run position, no difference)
TPS sensor. (Can't buy just a sensor, need to buy whole T-body)
I put on a new t-body and I regained my shift points, proper shifting and control of throttle. Yes a ported throttle body does increase response, but in this case it is throwing off a few settings the ecm looks for. Car would even stumble under acceleration because of it. The throttle body/drive by wire system controls quite a bit based on its calculations/proper range.
We need to figure how to tune around it, I'll be putting the ported unit back on and seeing what happens with the tune you wrote me that disables the code in the next day or two. Thanks again for your help!
No, the stock throttle open 100%. For whatever reason, the TPS voltage at WOT is only 4.35 volts, compared to a 5 volt reference, so when you scan the TPS value, it shows up as 87%. The ETC (electronic throttle control) PID will show 100%, which corresponds to the actual throttle opening.
