Thread: stock auto sentra XE won't drive. limp mode/cel

I just picked up this '93 automatic XE as a DD and it came with a "blown motor". Took it apart and all it needed was a new exhaust cam and gear. So i put it all together went to start it. It started up fine. Idled great etc but if i try to rev it up only to like 2-3k then the CEL will turn on until the rpms drop then it will go off and also if i rev it a little past where the CEL turns on then it will hit a rev limit which i assume is limp mode. I am good friends with Dudeman258 on here and he told me to check the maf or maybe even iacv but he wasn't quite sure how to go about doing it since he owns a se-r with a VE. My motor is a stock GA16. The second problem i am having is i tried to just move the car and when i put it in D it kind of idled down a bit then when i put it in reverse it idled down to a stall...Also if it matters the battery in the car is pretty dead and the car needs to be jump started everytime. So my questions for you guys...

Has anyone experiences this problem? if so what is it or what do you think it may be?

If i need to check the MAF how do i go about doing that? what voltage should i test for and from which wire etc.

Anything else i should check? it seems like the problem is sensor related.

How do you check codes on this car?

Clearly, i am a Honda guy so i don't know my way around these cars that well, any help will be greatly appreciated.

Update: checked the codes. It was giving me a MAF code so i checked the plug and it was loose and the clip doesnt really keep the plug on. Took it for a drive around the block. Everything else seems fine. The End.