P0300 & P1112 codes?

[Rich Z]

Now what? I got the check engine light on yesterday and just figured it was the rear O2 codes again from my header install. But I broker out the Predator today to check them out.

Hmm, got a P0300 code (Random/Multiple Cyl., Misfire Detected) and a P1112 code (Intake Air Temperature Sensor Circuit Intermittent).

These are both new ones on me.

Well I'm taking the Z on a jaunt tomorrow, so I guess I'll see what happens.

[Guro305]

Originally Posted by Rich Z

Now what? I got the check engine light on yesterday and just figured it was the rear O2 codes again from my header install. But I broker out the Predator today to check them out.

Hmm, got a P0300 code (Random/Multiple Cyl., Misfire Detected) and a P1112 code (Intake Air Temperature Sensor Circuit Intermittent).

These are both new ones on me.

Well I'm taking the Z on a jaunt tomorrow, so I guess I'll see what happens.

I'm just curious what happened with this? I used to get my check engine light to come on, then off all the time. Recently it came on and stayed on. What became of yours?

[Rich Z]

Well the IAT sensor had a bad wire on it, which Greg at AntiVenom fixed. That fixed the air temperature errors. This was also plainly visible when I monitored the IAT sensor with HPTuners as random spikes in the temperature value the sensor was reporting.

As for the Random misfires, that is still happening. I have been using HPTuners to monitor the misfires, and it appears to be something vibration sensitive, because it only happens when I am riding down our bumpy dirt road. Hits all cylinders and is not just one or two causing the problem.

I asked Greg to look for the problem this past weekend, and he did find a really boogered up ground that he thought was causing the problem. Unfortunately when I got close to home, I put the monitor on, and found out that the problem is still there.

So at this point, I still don't know what the problem is.

Here's a screen capture showing those misfires:

[Guro305]

I assume those screenshots are from a laptop. What are you using as far as hardware and software?

[Rich Z]

I'm using HPTuners (http://www.hptuners.com/), which is the software and the hardware. The cable acts as a standalone data capture device, and HPTuners runs on the computer. I have it loaded on both my desktop and my laptop, so that screenshot was actually taken from my desktop system.

[Guro305]

Sweet! How much did it run you? They don't have a price listed for just the cables and software. Can you also use it to make changes to the ECM programming or is it just a diagnostic tool?