I have a 2008 Honda Civic LX sedan with Automatic transmission. Two months ago I had my oil changed, but I don't think they rotated the tires. A few weeks later, I was driving in a bad rain storm and my TPMS light came on. NOTE: NOT the LOW TIRE PRESSURE (!) light. The TPMS light was on continuously and then I realized my rear passenger tire was leaking. The tire had a leaky valve core (I sprayed in the valve with windex and it bubbled like crazy.) So I went to WalMart and bought Slime brand 4 way valve tool with 4 valve cores. The package says "(!) Tire Sensor Safe" but who knows if they actually are. I unscrewed the old valve core and replaced it with a new one. After a few days of driving with correct tire pressure (I put 33 in all tires), the TPMS light went off. Now it seems to go off and on about twice a day while I drive around. Sometimes it's on, sometimes it's off.

Around the same time as replacing the valve core, I also had to replace my 3rd clutch gear automatic pressure switch because I was experiencing bad shifting, check engine light had come on (and would turn off at times) and had codes P0847 and P0756. Since then shifting has seemed better and the check engine light has not come back on.

Is my only option to head somewhere where they have a TPMS tool to have them do a reading to figure out what the problem is? My tire pressure has been fine, no drops.