When driving car sometimes it makes a loud sound as if the A/C were turned on and that causes the engine to feelforced

A couple thoughts. First, the air conditioning compression may be coming on even with the A/C "off" - because the compressor is being used any time the climate control system is on, for the most part. Even with defroster, floor vents, or another setting on, the compressor may indeed work. If there is a problem with the compressor it will show up at these times also. Engine performance issues could be occurring also, as evidenced by the existence of the check engine light being on. Even if nothing is wrong with the air conditioning system, the extra load it naturally puts on the engine could expose weaknesses with engine performance, causing rough and poor running. I would recommend starting by looking into the cause of the check engine light. Always fix what you know to be failing first before trying to go into areas where there are not clues present. The oil pressure gauge -- 350 degrees would be temperature not pressure; either way, seems erroneous; hands on testing definitely is recommended. www.repairpal.com/repair-shops