I have a '99 Accord EX (VTEC) 4 cylinder. Everything is stock.

I recently got an UltraGauge which plugs into the OBD II plug and reads out various parameters. The check engine light is not on, but I was wondering if the VTEC can malfunction without showing a check engine light. The engine starts well, but seems to run better and show better instantaneous MPG readings when I get above about 45-50 MPH (I guess the torque converter locks ups at about that speed) up through 70 MPH. It just feels like the engine is "getting on the cam" at that speed.

Can anyone tell me whether the VTEC on this engine is a simple on/off at about 4k RPM or does is adjust more than that?

I have been reading engine temp and it takes quite a while to get to 195º F or higher although it gets somewhat below that fairly quickly. Is the thermostat for this engine a 195º one or just what? (I thinking about replacing it as I am not convinced that it closes all the way.)

The intake temp runs anywhere from about 160º up to the 190ºx which seems a bit warm to me. (I am in Central Texas and the ambient temp has been above 100º pretty consistently of late.) I do not know precisely where the inlet temp sensor is located and whether it is measuring the actual temp of the inlet charge or the underhood temp. It seems like this is a bit warm to me, but I do not know what a "normal" reading for this would be. (It seems like it could benefit from a little cool air from the outside.

Using the UltraGauge I have noticed that the instantaneous MPG is pretty poor going up through the gears (automatic trans) and it seems to benefit from accelerating somewhat briskly to get into high gear quicker. Does anyone have experience with this or similar instrumentation?

TIA