Written by: webmaster
Function of the
Secondary air injection valve:
The SAI valve functions as a one way valve, which allows air to pass through the valve down stream into the air injection ports that goes to the exhaust manifold. It's only functions is to dilute the rich cold engine start up air/fuel mixture in the first 15-30 seconds of a cold start up before it exits to the atmosphere, also provide extra oxygen to allow the catalytic converter to be more efficient during the cold start up. installed immediately above the SAI valve is a check valve which is opened and closed by vacuum, when the SAI cycle is engaged the check valve is opened by the vacuum pressure to allow fresh air sent by the air pump to the SAI valve. The nature of the one way SAI valve prevents hot exhaust gases from flowing in the reverse direction and send hot exhaust back up to the expensive electric air pump. The check valve is an additional safety device to prevent the exhaust gas from going in reverse. So typically if you have a blown open SAI valve the check valve is also burnt up, as that's the design intention to protect the air pump.
Disconnect the battery at the battery terminal.
Unbolt the 13 mm air box bolt
Loosen the 7 mm intake hose strap
Pull the hose off the throttle body and
lift the air box assembly up and tilt it so you can access the back side
of the mass air flow sensor plug. I found that just thumb pressure
alone is not enough to unclip the plug to remove it, so you will have to
use a small flat screw drive to pry the clip up in order to remove it.
Unplug the throttle position sensor on
the throttle body and unbolt the four 13 mm throttle body bolts
Press the tab on the plug connection on
top of the central intake distribution tube
Loosen the four 7 mm intake distribution
tube strap and remove the intake distribution tube, there are two vacuum
lines attached on the back of the intake distribution tube, take caution
when removing the tube and tag the vacuum lines for assembly.
Loosen the coolant drain hose connection
bracket. The shop manual calls to remove the hose, but I didn't find
that procedure to be needed.
Use a 27 mm socket to turn the belt tensioner
clockwise to remove the belt. Mark the travel direction of the belt
as it needs to go back in the same direction. Also remember the position
of the belt arrangement, you might want to draw a picture to help you remember.
Unplug the vacuum line on the electronic
switch over valve (make sure you tag them as they get confusing later),
unplug the electrical connection to the valve and remove the two 10 mm
bolts holding the valve to the intake manifold. I recommend removing
this as it gives you more clearance to remove the alternator.
Remove the alternator idler pulley, and
then the alternator bolt
Taking out the alternator maybe a little
tough as it is wedged in the bracket pretty good. Try to use a pry
bar and lift it out of the right side bracket first and then over the lower
mounting bolt bracket so that you can tilt the alternator forward to remove
the electrical connection behind it. There is one plug and one 13
mm bolt to remove in order to remove the main power connection.
Remove the rubber hose from the air pump
to the check valve
Remove the electric change over valve on
front of the SAI valve by unplug the electrical connector and pull out
the two vacuum lines (Again you want to tag the vacuum lines for installation)
Now you will need a special tool to remove
the SAI valve, you can use either a modified 27 mm craw foot, or a 1" craw
foot widen and slimed down so it will fit beneath the SAI valve.
I had to remove the SAI valve with the check valve attached with the hose
as one unit as the hose clamp was in a position where I couldn't get a
good bite on it to loosen it.
Most likely if you are getting a check engine light with an error code of P0410 you have a bad SAI valve, and depending on the fault condition of the SAI valve you may or may not need to replace the check valve. You can check the function of the check valve by using a hand vacuum pump to activate the valve and try to blow air down stream and see if air gets passed. If the valve opens with vacuum and closes without vacuum then it is still in good working order.
Alternator - Once you wedge the alternator back in, mount the right side mounting bolt with the pulley idler first and then try to line it up with the left hand side bolt.
distribution tube - Attach the two vacuum line to the back of the intake
distribution tube first and then install the rubber sleeve on the intake
runner on the left side first and the rubber sleeve on the distribution
tube and then wedge the right side on first and then slide it all the way
to the right and then the left side. Do not tighten all 4 straps
just yet. You can tighten one strap on each side, as later you will
need to adjust the intake distribution tube to line it up with the mounting
position of the throttle body.
body adjustment - There is a bracket that mounts to the bottom left hand
side of the throttle body bolt. This bracket is used to determine
the position of the throttle body, once the throttle body is secured then
you can go ahead and tighten the rest of the intake distribution strap.