Hi all. New to the forum.

My car is a Volvo C70 2.3T 2004, 105,000 miles. I have posted elsewhere and had an array of suggestions, but without any codes to work from (OBD2 gives no codes), I don't know where to really start.

After some recent loss of power, I replaced the plugs, coils and air filter, all were much needed. She ran like a dream for a week or so until I noticed severe lag when I'm getting up to highway speed. My takeoff is pretty good (not fantastic) and the car idles fairly smooth at like 800-900 rpms. It seems to be in around 50-60mph, acceleration gets noticeably slow, and sometimes unresponsive. I sometimes have to literally kick down on it to make any gains. Usually the rpms wont even go up when firing the gas right away, until it all 'kicks in' a second or two later. I have had throttle body, maf, fuel pump and catalytic converter suggested to me. I think it sounds more like the first two and less like the latter. My car's check engine and ETS lights are not illuminating (they do work, as I see them when I turn the key over), and I am not giving off any OBD2 codes. I don't know where to start and would like to avoid a very costly trip to Volvo if it's a simple fix. I also don't want to just start replacing any and every probable cause, as I don't feel I have the time, means or know how for that. Overall, the car starts right up and runs fairly well, but I can tell something is off, and would like to address it rather than let it ride. Any information or guidance would be very much appreciated.

Thanks!