My 98 Max was running smoothly, but its been 4 years since I cleaned the Throttle and MAF.

I put everything back together and upon starting I get a really rough idle.

I didn't touch the idler screw, and I put everything back together, hoses and all, honest.

There is one hose that I have not seen in any picture here, it is right beside the only hose I have seen that connects to the left side of the Air filter assembly. WTF. I have no idea where it should go. Picture below:

Anyways, what the first step to diagnose this rough idle?

 

Is the car throwing any codes? What exactly did you do to the car recently?

Check for vac leaks and make sure all of the clamps are tight. Also, clean your TB, MAF and IACV.

 

No codes. As I said, everything was running smoothly, cleaned the TB and MAF.

And now really rough idle. One hose to the bottom right of TB was a pain to slide back all the way in, but I believe it is still tight and secure.

Any idea of that unattached hose just above the large hose to the left of the MAF/Air box? I don't see it in any pictures here, except mine above.

 

That is your transmission vent, it just hangs there. This all started as a result of cleaning your MAF and TB? What did you use to clean it?

 

MAF sensor cleaner and TB cleaner, the same as described on this forum.

Could it be the chemicals, and maybe MAF was damaged?

The last hose was secured and in place, but little change in idle, a pulsating idle.

 

Seriously?? Heres your problem. http://forums.maxima.org/4th-generat...le-gasket.html

 

the form a gasket sucks? Can it cause damage?

I used the non-permanent one.

 

I wouldn't use use it for a TB. I don't think it would hold the vacuum. You didnt leave half the gasket there did you?

 

Yes I did.

Can I at least drive for a couple days until I obtain a real gasket?

 

i know plenty of mechanics who've used gasket maker on TB's. you cant leave half of the old gasket on there though.

 

I installed a replacement gasket and all is well.

FYI, its better with a real gasket.

 

Just following up, about a day after I replaced the gasket, the service engine soon light appears. I run the OB computer and it is a 05-05 code, a false flag.

I cleared the code, and today while driving the light appears again.

I haven't check the code again, does thios happen a lot, the 0505 keeps appearing?