HAve been to this location before for flushes, etc and had no problems. However, after failing a smog test, I drover over here bc its close by. I wanted them to check codes and let me know what was wrong. About 5 hours later, they called to tell me that my ECM (car computer) and fuel pump were bad, and that there was probably going to be even more repairs needed once they got into it. My quote for the 2 things was $1600, and anything else they found was going to be more.
I went next morning, picked up my car and paid my $90 diagnosis fee. I took the car to my regular mechanic who checked everything and the only thing that was wrong with the car was a burned out check engine light bulb. Fuel pump was perfect, ECM working perfectly. He told me that there were old codes that hadn't been cleared, and once he cleared them, the CEL went off.
Went back to smog station next day, and passed with no issues. So, if you need your tranny fluid changed, this place might be ok. For real engine issues, go to a real mechanic. These guys are throwing darts at the problem and charging you for it. At the very least, get a second opinion before you green light any engine repairs.