Hello everyone I am new to this forum and would appreciate some advice and guidance on a few issues I am having. Car is a 1998 Accord EX 4dr 4 banger automatic and is my DD so A/C would be super haha.

1st: The temp gauge goes up very quickly after a cold start to normal operating temp (-30* outside temp reaches normal operating temp in 1 minute or so), and after about 15-20 minutes of driving start to make it's way all the way up. It seems to go up faster the warmer it is outside. I am thinking a gauge issue. gauge temp sending unit is new BTW. radiator is full, and car drives normal. Also used IR gun and temps at thermostat and coming out of the motor are normal. Been going on for about 4-5 months now and it still runs just fine. Am I correct in assuming gauge issue?

2nd: A/C works perfectly at idle and cruising around and such, but at over about 60 mph it no longer works and begins to blow warm air. I had the system checked and they said the system looks good, they found no leaks and told me it was fully charged and the pressures were where they should be. I have no idea what is going on and a search did not yield any results. anyone have any ideas?

Also CEL is on po420...cat below threshold. Searched and found this is common and nothing to worry about...so I am not lol, but I thought I would throw it out there to give you guys as much info as possible.

Thanks.

 

I would check the connection at the temperature sending unit is clean and secure. You may also be able to test the signal at the cluster.

On older accords, they had a coolant temperature sensor that the ECU uses and a temp sending unit that the temp gauge uses. Make sure that you replaced the sending unit and not the coolant temperature sensor.

The clutch on the A/C might be slipping at high rpms due to wear on the clutch plate. You can remove the pulley and remove a shim to see if it engages. A loose or worn compressor belt may also cause this kind of a problem.

The CEL means that the cat probably needs replaced. Aftermarket ones are cheaper. If you have emission tests in your state, you will have to replace for it to pass inspection.

 

Same thing on '98. Both sensors are in the end of the cylinder head. Sensor for the ECU has a 2-wire clip. Sender for the gauge has only one wire.