P0300 & P1112 codes?
 

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.

:banghead:

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?:shrug01:

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. :nonod:

Here's a screen capture showing those misfires:

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

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.

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?

I got the professional version of the suite, which runs $649. The reason I went with the pro version is because you can do data collection with just the cable and don't need to use a laptop for that function. The "suite" contains both the scanner and the PCM editor, but they do sell just the scanner portion as a standalone.

Here's the link to the page showing the prices -> http://www.hptuners.com/order.php

EFILive is another product that is very highly rated, and probably HPTuners major competitor -> http://www.EFILive.com/. They have just come out with new version which looks pretty handy, so I would give them a look as well if you are in the market. Price is higher, so I would try to do a point by point comparison to see which one you think would be better. They probably both will do the job, but certainly there will be differences that may or may not be significant to you.

So where does the cable hook up? I often have the laptop in the car already because I run a GPS on it.

The cable plugs into the PCM interface connector right below the dash. Just about right below the steering wheel. You can either use the cable standalone to do data capture, or you can hook it up to the laptop via a USB cable that plugs into the cable box.

With the laptop hooked up, you can set up a real time display of any number of the charts and graphs the program has available. For instance this one:

http://www.corvetteflorida.com/pics/hptuners_gauges.jpg

Admittedly, however, it can be rather distracting and probably better to keep you eyes on the road. But heck, I just love doodads and gadgets like this.... :D

I gotta get me one of those.

But I think that's where my WindowValet plugs in. I don't want to live without THAT! :) Maybe you can show me the hookup at UVP.