I have been having random misfires on cylinder 4 of my Toyota Camry when at low rpms like at stoplights for about 2 months now. It randomly happens and I think it may be effected by the weather as today it was sunny and 70 and didn’t happen at all today while yesterday it was in the 40’s and raining and happened bad enough that I finally got a check engine light to read, whether it is the rain or temperature I’m not sure. I had originally replaced the spark plugs since I didn’t have a check engine light to determine the issue until yesterday. I took it to a mechanic to get the reading and they told me it could be the valves. I’m wondering if that’s the issue since the mechanic wasn’t quite sure and if it would be possible to do a proper diagnosis and fix it myself since I am on a tight budget right now?
Did you try replacing the rubber spark plug boots at the bottom of the coils?
I had to replace the shims to get the valves adjusted right on a Miata. I think your car uses shims, too. It’s not a piece of cake and if you don’t have a full set of tools and a place to work, as well as some serious experience digging into engines, you might be over your head to do it yourself. It did need doing, and the misfire disappeared immediately.