Me78569

Welcome, nice to see more 4th gen people coming around.

Its time to put new tires on the 4th gen. the current tires are good for highway summer driving and have ~%25 wear left however winter is going to be coming and the wife will need better traction. I bought a 2nd set of rims stock 4th gen 275/70/18 tire size. I have been looking at a couple tires, but I need some input. Things that are important to me are wear life, cold weather traction, snow traction. we dont tow much right now, but it will be happening again soonish. I expect to see %95 paved road driving, but I do have a ~1 mile long gravel driveway. so far I have looked at Goodyear duratrac 275/70/18 load E - looks like a good all around fit. BF goodridge TA k02 - looks good on papre, but reports are that they wear quickly with the K02 model GRABBER A/TX - good reviews DISCOVERER AT3 XLT - had a set of AT2's on my old truck and winter traction was not great.

I believe it should be voltages between 4.5 and .5 voltage. I dont remember if the sensor is a pull down or pull up sensor. So at 0 psi I would expect to see either .5 or 4.5v, then as boost comes up I would want to see voltage change. I've never been able ot have hands on a truck that does what yours is doing so I am only guessing, but maybe the 5v bus is off causing that 0 psi reading to hold on longer? I dunno.

Consider the useable life of the vehicle vs the cost. 200k miles vs 60k miles is a no brainer for me.

If the part is bad I would replace it. Were there codes for the apps?

You can't blindly set apps voltage, they are calibrated by the manufacturer. My guess is you set the voltage way to low and you are having to increase tps to ~10-20% before the IVS ( Idle validation Switch) is disabled and fueling occurs.

Is it a stock style apps? If so you should not set those to voltage as they have a multi part system for knowing when at idle state.

Follow the tuning guide steps.

Yes. Couple of guys tuned down 7 x .011 and .012 to run with a hx35

I wouldn't bother it's just the ecm being the ecm. No real issue.

Semi normal with big injectors and a tune. The ecm is in control at this point and it is trying to manage rpm vs fuel. The ecm is programmed to think it needs xx% duration to keep idle. Bigger injectors means it only needs yy% so it drops fueling but it overshoots then fuels harder and then overshoots and repeats

Its awesome when you get to experience something like that with no one else there.

However there is an issue if the ecm is not seeing good boost reads. My truck was perfectly accurate until ~25 psi. question is would low 5v source to a 5v reference sensor cause a lazy map read? Maybe a damaged voltage regulator on the 5v bus?

The main thing is below 16 psi. When boost is below 16psi the quadzilla is reading the canbus message and sniff out the reported boost number from the ecm. It is NOT reading the sensor directly. In situations below 16 psi where boost on the quad is not matching a mech gauge we know for a fact that the ecm is not getting an accurate read from the sensor or the ecm is not reporting an accurate read on the canbus. This is not a quad issue rather an issue somewhere else in the system. Boost numbers over 30 psi not being accurate are not really a big issue.

the issue is the ECM isn''t seeing accurate boost. That's where the fueling starts. you can tweak the bottom end to make up for this, but you will loose a lot of smoothness.