Pulled codes on Service engine soon light

[reduas1]

I just had the codes read at the auto part store on my 2001 QX4. The Service engine light soon light has been on for about a month. The car is running normal and no noticeable decrease in performance or gas mileage has been noted. The codes are PO430, P1140, PO420, P1145. What are these codes, and do they indicate a serious problem. Thanks in advance for any help.

[1qckser]

Welcome aboard, im sure you will get more answers if you try a search first, I know I had a post about one or two of those codes, once again good luck and nice to have ya.

[94q45t]

What fun this will be. When you get multiple codes it doesn't mean all those things are wrong, only that the ECU thinks they are. I once had a dealer tell me I needed a $2500 wiring harness on my 00 Maxima (it had 40,000 miles at the time and threw multiple codes). Turned out to be a bad MAF. Another time, the code indicated a transmission fault (01 Pathfinder), but the real culprit was a bad intake air temp sensor. This isn't nearly as precise as they'd like you to believe. The real solution is to find a good tech who is very knowledgeable on engine electronics.