any idea on what could have happened

 

maybe you damaged the maf sensor

 

you have to be REAL careful when cleaning the MAF, did you take them out and clean them, or did you clean them while they were still on. if you cleaned them while still on the car maybe your engine sucked in all that gunk

 

Explain running rough...can you rev past 3500 rpm or so ?

most likely you Bucked up your maf, cause there is no way a TB cleaning will make things worse, did you also replace the TB gasket ?

 

And hopefully you put them on back together correctly.

 

took the maf assembly apart from the airbox and sprayed it down. let it dry then reassembled it.

it was on my father's max. he's been having this riunning rough and mpg problem for about 3 months. and this took care of the CEL.

i'm thinking he had a bad mafs from the start and cleaning it made it better but did not cure the problem.

 

BINGO.... what was the cel code ?

if it was for maf then you know its your maf, cleaning it may have gotten rid of it for now but you are just masking the problem.

 

it was a misfire code

 

a misfire, eh? wunderbar

 

was it specific to a certain cylinder ?

PS: in general you got listen to the ECU when the code appears read it , its telling you whats wrong, why would you clean the maf for a missfire ? im no nissan tech, but how are the 2 related ?

 

It was a specific Cylinder.

I changed the spark plugs and checked the coils, which were fine.

By cleaning this MAFS the code has not come back, but is running funny.

i was just told the reasoning for being a bit wierd on the road was because of his tires.

but we both did our TB and now when i start my car it tends to idle a bit higher than before. Maybe there is still Gunk it's burning?

 

no the idle will be higher after cleaning the TB, leave it its normal and should settle with time

the code tho thats the real mystery (at least for me)

 

I have the same problem. After cleaned a throttle body and IACV with replacing the gaskets, the MPG is dramatically dropped from 330 miles(16 gal.) to 230~250 miles(16gal.) now. The car is always feeded on a premium shell (Oct 93).
Thanks.

 

it should go away after awhile mine did after only about 100 miles