Overboost code with Stage 1s

[rolsmojave3]

Anyone getting boost sensor high codes? I believe it was a PO238. Only happens in 140hp tune. As far as I know the truck only has stage 1 injectors, no turbo housings or anything. Usually can get the CEL to come on near or above 35psi of boost.

[jesilvas]

Umm, well duh. 35PSI will throw an overboost unless you have a boost fooler.

[rolsmojave3]

Hey thanks, I didn't know this.

[jesilvas]

I'm surprised your tuner didn't mention this to you when you had him tune for the S1s.

[rolsmojave3]

I talked to PHP they didn't mention it, I see they have it listed on the website, however when ordering I didn't see a spot to "opt" out of a certain DTC.

Not a big deal, I just wasn't aware the OBS trucks did this.

[anschutz1913]

I didn't think the OBS had over boost code.... Perhaps I'm wrong?

And if so then does the truck start to de-fuel on the top end when the code hits?

[rolsmojave3]

You can tell it looses power, It's only in the biggest tune which I rarely use, so it's not a huge deal.

[1Dieselman]

It doesn't de-fuel, it slows the input from the IPR (IIRC), also takes at least two consecutive overboosts to set a code

[BigFuel]

Originally Posted by rolsmojave3

I talked to PHP they didn't mention it, I see they have it listed on the website, however when ordering I didn't see a spot to "opt" out of a certain DTC.

Not a big deal, I just wasn't aware the OBS trucks did this.

Grab a cheap air pressure regulator and gauge installed into the "gauge" port. Plug the "out" port. Hook it to a air pressure source with a known pressure higher then 50PSI. Set the cheap regulator to 23PSI. Install on the MAF feed hose that is between passenger intake manifold and MAF port on the firewall with barbed fittings and hose clamps. Now your PCM will never see the full boost and continue to fuel as normal. Start truck and hold on!