So da neon is dead.

org05neon · Post by **org05neon** » Sun Sep 23, 2012 11:37 pm

Since I have to replace the valves on the head after the timing belt broke.

Should I save up and do a new cam, over size valves, and have the head port and polish. Will all the upgrade made a diffence with ngc motors?

Post by **occasional demons** » Mon Sep 24, 2012 9:25 am

Soda Pop.

It will make a difference. More air will force the PCM to add more fuel. It is not sensor parameter that is tweaked electronically, but a physical change that the PCM must compensate for.

But you may be limited to the stock TB, as the increased air flow will make odds of setting the MAP/TPS correlation code even greater. With an '05, you are pretty much stuck with the stock TB anyways....

IDK if anyone has pushed the limits of what the head/valvetrain can flow to set the code with the stock TB.

But you are going to spend a small chunk of change for all that. Whether or not the $ is worth the gain is up to you.

stdlystdmufn · Post by **stdlystdmufn** » Mon Sep 24, 2012 6:07 pm

i had an 05 that i put a 60mm tb on and all i had was a header, mag IM, AEM CAI, and catback 2.5" and i set the correlation code. but when i put a indy P&P mag head w/ comp 400, same header but with a custom bent 2.5" header back exhaust with 2.5" cat, AMM IM, RAI and same 60mm TB and never got the code again. so i think the code may be counter intuitive. in that the more efficient your motor pumps air the less likely you are to get the map/tps correlation code...but then again maybe mine was a fluke.

Post by **occasional demons** » Mon Sep 24, 2012 6:18 pm

I think it was Danman R/T that had it happen the opposite way. It was fine until he added the 400 cam and a few other things. But IIRC, his is an '04.

Basically anything that makes the manifold vacuum too close to atmospheric pressure for the throttle opening will set the code.

esteinmaier · Post by **esteinmaier** » Mon Sep 24, 2012 8:25 pm

OD, it will actually have the opposite effect as the symptom of the TPS correlation code. The code is set because the MAP reading is too high for the observed TPS value. By increasing the efficiency at the head, as long as there is a little load, the vacuum will be higher from the added efficiency pulling at the intake valve. Of course, that's only true if the RPM is high enough that the changed cam profile is helping instead of hurting. But the code tends to trigger in those ranges anyway.