intermittently drives well
Ok, I have gone through so much with this car I am going crazy. I have already thrown over 1400 dollars into it and still something is wrong. I am bonkers, I just need an answer. The most recent change is new cats. I drive, and it misses, and has no throttle response under load, and even almost dies. I can floor it and get absolutely nothing. When in park it sounds great, and it doesn't appear that getting to temperature changes this variable. There are no codes, and no pending codes. There is no reason that it shouldn't run great. Then, the best part, for no particular reason whatsoever, while driving, it drives great and gies me all the throttle I want for an indeterminable amount of time. The car will not hold speed, at all, ever, for no matter what I do I cannot figure it out. I have new plugs and wires, new 4 o2's, new intake gaskets, cleaned all of my sensors, maf, ait, throttle position, iac. I have a fresh oil change, new air filter, new fuel filter, and new fuel pump. I also now have new cats, and I don't want to ruin them. I am at a loss. I think it is an injector, because only the drivers side cat glows, and only intermittently. How can I tell? I also think that there is a vacuum leak. I also think that there is an exhaust leak at the manifold "it is missing two studs" but it doesn't sound like it. I am not driving it or putting any more money in till I know what it is.
thanks for any and all help,
Kevin