Failed Emmisions and hose leak

[OnTheRoadAgain]

1. My 91 Q45 failed emmisions for "No" it was only slightly above the spec

2. found a hose leak, upper section of lower radiator hose goes under plenum / manifold. Have to remove the manifold? LOTS of labor?

any advice appreciated

[Haitian_King]

Plenum removal is a little time consuming, but you get faster at it with practice. If you're going to remove the plenum, you might as well replace all the hoses, check the injectors and knock sensors. Take care of the under plenum stuff while it's off so you don't have to take it off again for a while.

We'll need a little more to go on, like what state did the emissions test happen in? How's the engine running? Any smoke or smells?

[goody90q45]

1. My 91 Q45 failed emissions for "No" it was only slightly above the spec.

No is NO=Nitrous oxide. Do you have any ECU codes? Have you changed your O2 sensors lately or ever? Mileage? If you've never done this new O2 sensors will reduce your emissions and pay for themselves in a few months with the improved gas mileage.

Is your engine running/idling a little bit rough? You could easily have a marginal or bad fuel injector or two. Ohming injectors is a simple DIY and you may as well check the KS while you're there. Check the ECU codes and ohm the injectors and you should have a pretty good idea of why you're failing emissions. Let us know what you find.

[Q45tech]

NO failure is always the result of dirty or defective EGR system.First place to look is a plugged passage into bottom of plenum port just after throttle body then clean outward from there all the way thru exhaust tube to exhaust maniforld................use homemade rotorooter from a flexcable and handdrill................disassemble parts as need to insure cleaning.

[OnTheRoadAgain]

Tech said exactly that, they cleaned a few egr ports and is ok now

back to the plenum water hoses.do you need to remove the plenum AND manifold or just plenum; he says labor is half for just plenum? How much labor time?

Thanks for your help!