shafner30

so I'm getting a smelly exhaust sometimes not all the time on my 1990 toyota pickup 22re I can't figure it out any suggestions ?
btw The truck runs great just just smelly exhaust sometimes

mattyboi

Does it have a cat?

millball

Does it have PAIR??

shafner30

yes and yes

millball

PAIR is supposed to work at idle speeds, adding clean air to the exhaust stream so as to reduce idle speed emissions by giving the cat more oxygen to use on unburned hydrocarbons..

Engines run rich at low RPM with no load.

If PAIR operation was intermittent, it could be your issue.

Open loop and closed loop fuel management regimes could also account for your intermittent trouble.

Open loop operation tends to give richer mixtures than closed loop does.

wallytoo

iTrader: (1)

check for exhaust leak someplace before the cat. after the cat generally does not change the odor.

shafner30

how do u check the PAIR system ? how do they fail ? do u just check the hoses coming from the air filter ? does the pair system fail often ?

millball

My experience with PAIR is somewhat limited, but my '88 22RE Runner is equipped with it and when its engine is idling, I can hear the PAIR pulsing at the air cleaner air box.

It is just barely audible to me. When I rev the engine above idle, the ECU tells the PAIR VSV to stop sending vacuum to the PAIR reed valve and the pulsed air sound stops.

Same thing if I disconnect the vacuum line between the PAIR VSV and the reed valve while the engine is idling, I can hear the PAIR stop functioning.

As to anything else, maybe somebody else can chime in, or you'll have to consult the FSM for testing info.

Kolton5543

What does it smell like. Does it smell rich, burning oil, or rotten eggs. Rich could be all kinds of things. Oil could be rings, valve guide seals or PCV. Rotten eggs is usually a stuck open egr