I recently bought a 2003 Honda Civic LX 5 speed and I have replaced the coil packs spark plugs the air filter and the thermostat. Before I made any repairs to it all four cylinders had a misfire and a code came up for the ignition coils. Because one of the folds broke off to hold the coil on there Which is fixed now. After clearing the codes and running another scan it's coming back cylinders two four and a random misfire. also the O2 sensor CAT and EVA. So after I replaced the thermostat the temperature gauge it still fluctuates sometimes mainly when I stop or in 3rd gear but my car is not overheating . yesterday when in third gear it started having like a really rough misfire . it's never done before . My car doesn't want to gain power in fifth gear It doesn't lose power but it doesn't wanna go. I was going through the manual and the car's computer was replaced at 77,758 miles back in 2010. I'm thinking this car is either got computer issues or the head gaskets needs to be replaced. Has anybody else had these issues in I bought the o2 sensor and the gasket set yesterday. I'm about to take the cat off and clean that n out the o2 in today. But I cant do the gasket til the wkend.. Also I forgot to mention but when I turn the air conditioning on my car smells like straight up fumes.. only the ac?
The cluster's been replaced on the car it's saying over 300,000 miles I'm not sure how many miles are actually on the vehicle the timing belts also been replaced back when the computer was I guess.
Hoping someone can point me in the direction to save me $$$ I paid 1500 for the car.. and Im dumping more and more into it!
PLZ HELP​​​​​​