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i have a 4 cylinder 92 mustang lx. Most times when i take off in my car it bogs down and its kinda like its not gettin gas, i have hooked up the computer to it and it says that the egr valve does not open. I was wonder if that could be it, or what. I didnt have a air filter in it and then i finally put one in it and it does do anyhting any better i ahve also changed the spark plugs and wires. I have put a custom exhaust on it, it is from a crx and it was a cat back and i have a inport tip on it. Could that be any problem, i have also checked the fuel pressure it says its fine i also put a new filter on it. I checked the vacuum pressure and its fine too i cant seem to find out whats wrong with it if anyone could help me htat would very sweet thanks very much.