Little info - this winter I installed a G5X3 cam, AFR 205 heads, caddy lifters, Melling oil pump, etc. I had my computer bench tuned to account for the above mods. Car ran PERFECT, except for my oil pressure was too high, (assumed pump problem), so this week I replaced my oil pump. When I replaced the oil pump, I added a Vararam and a Ported Throttle Body. The Vararam and Ported Throttle Body are the ONLY mods or changes made since my winter h/c mods. Remember, the car was bench tuned for the h/c mods and ran PERFECT until I swapped the oil pump and added the Vararam and Ported Throttle Body.

Before I added the Vararam, I talked w/ my tuner, and he thought the bench tune that he did would be sufficient to compensate for the Vararam and the Ported Throttle Body until I can get it dynoed. He didn't think the Ported Throttle Body would affect things at all, and he thought the Vararam might cause some roughness, maybe.

So, here's the problem: I started the car up for the 1st time last night after I finished the oil pump swap, and the Vararam and Ported Throttle Body install. DIC system shows Reduced Engine Power, Service Traction System and Service Active Handling. I have the following CODES: 10 - P1120HC, P1220HC, P1516HC
28 - C1278H
99 - B0446H

The B0446H code is A/C related so I'll worry about that later - (alright, for those of you in the know, could I be getting the B0446H code due to my A/C system NOT having any freon in it?)

My bigger concern is the P1120HC, P1220HC and P1516HC codes. According to my shop manuals, these are all Throttle Position Sensor Codes, and these codes can trigger the "Reduced Engine Power" message. I'm wondering if the Ported Throttle Body I added is bad? I bought it used, and this is the FIRST time it's been on my car. After my h/c swap when the car ran PERFECT, I was using my stock Throttle Body.

1. So, do you think the Ported Throttle Body is causing the above three codes (the 10 PCM codes)?

2. Is it because the car needs tuning for the Ported Throttle Body, OR is it because the electronics on the Ported Throttle Body are bad?

3. If the electronics on the Ported Throttle Body are bad, is it possible to swap the electronics from my stock Throttle Body to the Ported Throttle Body? The Throttle Body electronics have 4 tamper proof torx screws on them and they do not appear to be a servicable item according to the shop manuals - nonetheless, any problem swapping my stock TB electronics to the Ported TB - would this perhaps cure the problem? There is a gasket between the TB electronics and the TB; if I swap electronics, can this gasket be REUSED, or where do I get this gasket - or do I make a gasket?

4. Maybe I should put my STOCK TB back on the car and see if that cures the problems - then I'd know it is a problem w/ the Ported TB?

5. IF I were to put my STOCK TB back on the car today, can I REUSE the TB / intake gasket that I just installed yesterday? The shop manuals say to replace the gasket when you remove the throttle body, but this gasket has not even been compressed for 12 hours yet - would it be necessary to replace it?

Now for my question about the 28 - C1278H code - That is a traction control code which according to the shop manuals can trigger the Service Traction System and Service Active Handling Messages - I am wondering if I am getting this code BECAUSE OF A PROBLEM WITH THE TB also? Reason I question this is that the info in the manual says something about when the computer senses a problem with traction control, it reduces spark, does something else with the amount of throttle you are allowed to use, etc - Any thoughts????

 

Quickest thing to do is put the other TB back on and see if they go away. If they do, swap out the TPS (you need a security torx socket for this) and see if the ported unit will then operate correctly. Other option would be to switch the TPS first, but that adds a variable and I would just swap the TB's to start.

Good luck.

 

Problem solved, I believe - here's the deal

The Ported Throttle Body I bought was used - and I'm going to follow up on that - read on and you will see why!!

I read my shop manuals, and learned the Throttle Position Sensor (TPS) is on the throttle body (pass side) - so, I figured maybe the TPS on the Ported Throttle Body was bad, so I decided swap it - THAT'S when I noticed that the 2 tamper proof/security torx screws on the TPS on the Ported Throttle Body AND the 4 tamper proof/security torx screws on the Throttle Actuator Control Motor (on the drivers side of the TB) had been PREVIOUSLY drilled out so that someone prior to me could use a regular torx socket in these screws

To shorten this story up a little whoever drilled the tamper proof/security torx screws out messed up the torx head on the 6 screws themselves, so I had to remove the Ported Throttle Body from the car, take it to my workbench, and try more than a few things to get the screws out

I swapped the TPS from my STOCK throttle body (I knew my stock TPS was good) onto the Ported Throttle Body. Then I debated swaping the Throttle Actuator Control Motor (TACM) from my stock TB to the Ported TB - did I need to or not?? I took the TACM off of the Ported TB first, and I didn't notice anything AT FIRST! I then took the TACM off my Stock TB, and lights, bells and sirens went off!!!

When the TACM is removed from my STOCK TB, there is a large gear/spring assy on the TB butterfly shaft - then there is an intermediate gear which simply slips on a shaft on the TB; the intermediate gear goes between the gear on the TB butterfly shaft, and the gear which is on the end of the TACM motor -

GUESS What??? There was NO intermediate gear on the Ported TB!!! Someone had messed with the Ported Throttle Body prior to me, and REMOVED the intermediate gear - the TACM on the Ported TB was not even able to move the butterfly on the Ported TB, because the gear was missing

So, I swapped over the intermediate gear from my STOCK TB, and I put my STOCk TACM on the Ported TB, put the PORTED TB that now had my stock TPS and stock TACM on it, back on my car - car fired up, NO problem, NO check engine light, and ran FINE!

Drove car around town and out on the highway, runs fine, and my original oil pressure problem seems to be corrected.

NOW, to track down some info on the Ported TB!

 

OOOhhhh, crap, that would definitely be a problem. Glad you figured it out.

 

I just ordered a ported throttle body from Shaner. It doesn't come with any of the electronics, just the ported throttle body. Once I have my stock throtlle body out, do I just unbolt the torx screws from my stock throttle body's electronics and transfer them over to the ported tb? Any and all help is greatly appreciated!!

 

Mark does nice work. Yes, just transfer over. You will need "Security" torx bits, you can get a cheap set at Autozone. As stated above, take note of the Throttle motor assembly when you take it apart, you need to transfer the gear as well. Take some photo's as to disassemble to ensure you know how it goes back together, but its actually pretty easy.

 

Thanks! I'm surprised that as many as he sells, he doesn't have a link for installs on his homepage for idiots like me! Thanks Again!!