I started getting a flashing check engine light when I hit 30 mph. I was thinking it was a misfire so I changed the front 3 and the back spark plug (back furthest right) and wires. I still get the flashing check engine light but now it happens at 60mph. I am hoping if I Change the other two spark plugs it will solve that problem.
BUT my car is also shaking while idle and while in drive. It does NOT shake while turned on in park. The belt seems like it is making a squeezing noise, but I think it is from one of the pulleys...I just don't know how to narrow it down. Also the heat recently stopped working. The air comes on but the heat is barley warm. It's been 10-30 degrees around here so I have not had a chance to check if the AC even works. Anyone have any suggestions. I think I can fix most of the problems myself. A local mechanic told me it would be 200$ to change the spark plugs and cables. I was able to do 4 and change all the wires in 30 min for 50$.
Any suggestions?