I got a 94 Z with auto trans. The car has high miles and I can hear a ticking from the heads. When i give it gas it backfires through the intake and letting off high rev it back fires through the exhaust. I figured the SES light would throw a code, but nothing. replaced all the plugs and wires for no improvement. whats my next move?

 

its very easy to say it could be your opti, but have u checked fuel pressure or compression?