I ordered a mass air flow sensor for a 1994 Nissan hard body truck with a 2.4L engine from PGauto. I visited the site a number of times to make sure the part was the correct one. It arrived, I put it on the truck and the truck would not produce RPMs higher than 2000 RPM and would vary by 200 rpm up then down and so on. Which was the problem with the old MAF, however with the old one the truck would get to 3000 rpm before the up and down of rpm. I broke one of the two sensors so I could not return the product. The folks at bonanza sounded like they would have done that but... the original part was made by Hitachi. The part that did not work was a "replacement" for the Hitachi part. Bottom line it did not work out of the box! The next day I ordered a Hitachi MAF! When it arrived I put it on and no more fluctuating! The only thing I can concluded is either the part from pgauto is defective OR the web page at pgauto says this part is a replacement part for the Hitachi is wrong. Either way I will never order anything through bonanza and certainly not from Pgauto again. The part number from Hitachi is AFH55M10. pgauto replacement is 7450052. I just visited their site and it said their part fits 1990 -1996. Cannot be! I should have paid better attention! Poor poor product! I compared the 740052 with the AFH55M10. The sensors on the 74 part were black like they had a coating. The AFH sensors were white. The old AFH PART Were black until I cleaned them with MAF cleaner. Then they were white.