db4690, Common_Sense_Answer :
Yeah - I'm not sure about this Scan Tool. Just got it. It's a little weird in that I can do the 3 Data Captures while the vehicle's operating, but then I can't view the data offline (inside the house). When I try that - even though the 9V battery is installed to retain the data, it shows the 3 Captures, but all 3 have the same data. It's not until I go back out to the vehicle and hook it up again that I can see the 3 distinct sets of data. I could also hook it up to the computer and download the data that way, but I think the 9V battery is supposed to retain the data AND allow you to view it offline - but maybe not on the unit's screen - which, if true, is kind of weird!
Anyway, as for the petroleum jelly, I just put a thin film on the gas cap seal. It definitely made a difference, holding off the code for much longer than it had been happening. It was kind of an experiment to see if I really needed a new cap. The cap seal looks perfectly fine and so is the filler neck. No problems with either, but maybe the seal is just hard and not pliable - which is why the Jelly "fixed" it (for a while).
BTW: the P0442, I believe is just a side-show here. The real problem is an intermittent weakening of the idle at a stop which can work its way into an increasing stumble, and then ... POOF ... a stall. Never illuminates the CEL. Never happens in the morning on the 30 mile drive to work, and it won't happen on the ride home if I use the Interstate, either - because the engine is going full throttle most of the way. It happens if I go through town, with all the lights. As I get closer to home, say 3/4 of the way or more (~18 miles), stopping at a light can be "iffy". First few stops are no problem, then I stop at a light and I can start to feel the faint stumbling idle starting its death spiral (but not always). So it's related to the vehicle getting hotter, or running longer, but if I just use the Interstate the entire way ... no problem.
However - I have noticed numerous "stumbles" or apparent mis-fires while running at 70 mph on the Interstate. But never any MIL lamp illuminated. That's why I bought this Scan Tool. Thought maybe I could trap a buried code that just wasn't setting the MIL lamp ON.
As for the "General Discussion" comment, wasn't sure what you wanted there at first, but now I see, so I'll post over there, too.
I think the VSS shows 0 MPH because I activated it just as I was pulling out of my parking spot. It takes about a minute or so for it to Capture all its data, and maybe it's stupidly capturing the VSS right at the beginning and then ignoring any uptick? I mean, I had to go through (2) automated gates, so I wasn't able to get up to more than 25 mph, and only for a very short time. You'd think it would've shown some non-zero value, though. In general, I've noticed the speed Captures have been on the low side. Doing 70+ on the Interstate today only showed up in the 60's ... ???
Yeah - I haven't really tried to digest the data yet - that's why I went ahead and posted it first. Just trying to figure out if I like this Scan Tool or not. Initial reaction is .... I don't think so ...
Here's todays Captures: all contiguous, #1 from my driveway, #2 from a Stop Light about 10 miles away, #3 On the Interstate again .. going 70+ (but the Capture doesn't show that)