l purchased a 1995 Infiniti J30 a couple days ago. Everything was fine until now -- car stalled and threw a check engine light. l pulled the codes and got a code 12 (Mass Air Flow sensor) and code 34 (knock sensor: probably due to putting in regular gas by accident -- was used to my routine of putting in regular, caused pre-detonation). l backprobed the MAF and voltage was way below spec -- 0.012, minimum spec is 0.8. I am wondering, though, if a bad MAF could also cause the engine to stall easily, stumble when at WOT, and most importantly, have the ECM limit the RPMs to 2,500. Also noticed a smell of raw fuel in the exhaust, presumably due to an incorrect air/fuel ratio due to the bad sensor. Did not get any misfire codes either. What symptoms would a bad knock sensor cause? Checked continuity between the MAF connector and ECU connector, continuity existed. Anything I am forgetting to check? Any other possible causes for the stalling/2,500 RPM limit?

Thanks for any help/suggestions.

http://troublecodes.net/infinity/