having some issues geting computer ready for emissions test

04sxt2.0 · Post by **04sxt2.0** » Thu Oct 30, 2008 8:52 pm

ok here is my delima, i am trying to get my ecm ready for the massachusettes emission test, it keeps showing up as catalyst and o2 sensor are not ready, so i drove it to hartford and back which is about 25-30 min drive each way, and tried it again still isnt ready so i took a look at the freeze frame data with the emissions machine, coolant temp is at -40, fuel trim is at -100 both long and short. ignition timing is at -64.0 and intake air temp is at -4, now there is no CEL on and no codes stored, any help as to what you might think is the issue, no drivablility issues at all. about two months ago my car blew the main starter fuse in the fuse box, and ran through all the fuses, and removed them and checked them, i thought i might have shorted out the ecm so i pulled one connector off to check it was good,

now i am a mechanic for nissan and i know normally when he have these types of freeze frame data it normally means its got a communication problem with the CAN network and or the engine coolant temp sensor is dead. i am stumped right now fiqured i try here first before she goes to the dealership.

Swordfish2Cowboy · Post by **Swordfish2Cowboy** » Fri Oct 31, 2008 2:29 am

Holy shit, what?

04sxt2.0 · Post by **04sxt2.0** » Fri Oct 31, 2008 7:01 am

My car isnt passing the Mass emission inspection, it keeps saying that the cat and the o2sensor is not ready. i have driven it considerable distance to get monitors ready, even tried to reset ecm and try to set the monitors over again. still no luck, my freeze frame data is in the negative's any idea what could be wrong.

Post by **occasional demons** » Fri Oct 31, 2008 7:28 am

Well I have no clue on the FF data, but by cat, do you mean the down stream o2? Possibly the ground path in the PCM is bad or the wiring to the PCM. The upstream and downstream both share the same ground. One would think there would be some other issues if the ground wasn't there, but it might just be corroded somewhere, not giving 100%. Maybe check all your grounds for shits and grins. For the coolant sensor, if the temp gauge is working I think it is fine. It only has two senders in it: one for the PCM/gauge and one to tell the PCM to switch the radiator fan on/off.

04sxt2.0 · Post by **04sxt2.0** » Fri Oct 31, 2008 5:25 pm

i checked it today with a matco scan tool still no codes, as for radiator fans everything is tunring on and working fine, engine runs fine, just dont now why the FF would show it -64.0, it technically shouldn't even be runing then. i am probely going to call the dealership monday or sat,

Donkeypuncher · Post by **Donkeypuncher** » Fri Oct 31, 2008 11:47 pm

After about 60 miles they should be reading "ready", so it's kind of hard to say. The stealership just might be your best bet. I would think you could just get an inspection sticker from your nissan dealership, just depends on how strict your county is about them.