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So I need a new EGR boost sensor?

Or do you still need the cold, warm, and driving down the road numbers?  

I don't have e-check where I live so as long as it's not going to make the car run bad or cause harm in any way it should be okay to just leave as is?  

i have not found out exactly how to test the EGR boost pressure sensor..   it seems to be a vacuum sensor.. telling the computer how much vacuum is applied to the EGR valve.. so the computer can control how far the EGR valve opens by activating the EGR solenoid.. it dumps vacuum...  pulsed dumps reduces how long /much the egr is open..

one warning..  if there is NO EGR function..  it can lean out the motor..  cause damage...

what..

during normal engine operation. the engine fuel ratio is controlled by the feed back from the oxygen sensors..

under moderate and heavy acceleration..  the system drops out of closed loop... into open loop where it is under PREPROGRAMMED fuel control...  which is calculated with EFR function included..  if the EGR is disabled..  there will not be any Burned gasses entering the intake manifold reducing/diluting the effective oxygen content... so with the additional oxygen content.. the air fuel ratio will be on the LEAN side when it should be rich... and engine damage.. mostly melted piston skirts and then torn out piston rings happens as the pistons and rings try to slide through the aluminum welded to the cylinder walls by the melting pistons..   if this will effect your car.. i don't know..


i don't have enough info on hand to really diagnose this failure..  eautorepair.net or alldatadiy.com both have short subscriptions to factory service manual electronic versions..  there might be info there on how that works..

the scan tool might show that sensor data...  

With everything that you've provided me with I should be able to get it figured out. You've been a tremendous help and for that I'm grateful.
Thank you  

you are welcome..  have a good holidays.,..

post what you find.. ... there are lots of other people that read these forums.. .

its a LOT easier to do in person..  but i try my best...  

Well, it looks like the EGR sensor issue is solved (knock on wood). What I did was run a guitar string (pipe cleaner probably would have been ideal) through the nipple on the back of the intake ( fire wall side) that the EGR solenoid vacuum hose connects to and cleared out the black junk, then turned off the CEL and have been through two run cycles and so far no P1195 code.

Also, wayne, I checked the distributor cap with a meter and it's okay. So I went ahead and checked the valve clearances to see if out-of-spec valve clearance is the cause for the misfire on #3 cylinder - and it's looking like it is.  

The valve clearances are all pretty much within spec except for the intake valves at cylinder #3. The valve clearance on the left of this cylinder is .006 in. and the one on the right is so tight that I couldn't even get the thinnest gauge, which is 0015 in. in between the lobe and the valve to check it.

So I'm going to try to figure out a way to adjust the valves with common tools instead of buying the expensive specialty tools that the manual calls for. So if you have any ideas or know how to do it with common tools feel free to let me know.

Oh, I forgot to mention. The shop manual has .010 in. – .012 in. as acceptable valve clearance on all the valves for this engine.  

Lash Adjusters/Cam Followers
See Figure 25

For engines which use rocker arms, refer to the Rocker Arm Removal & Installation procedures earlier in this section.

Remove the camshaft(s)
As a precaution, to avoid mix-ups, wipe the oil off the top of all the lash adjuster/cam followers and, using a permanent type marker, label or number them. On DOHC engines, also designate whether the adjuster/follower is on the intake or exhaust side.





Fig. Fig. 25: With the camshafts removed, simply pull the followers from their bores using a magnet

Use a magnet and pull the lash adjuster/cam follower from its bore.

On non-hydraulic cam followers, the adjustment shim may come out of the follower before the follower is removed from its bore. If this happens, remove the shim from the magnet and repeat the removal procedure until the follower is removed. Place the shim back onto the follower.

Arrange the adjusters/followers, on a clean work surface, in the order that they are removed.
Installation is the reverse of the removal procedure.


wayne's instructions below... this is how i do it..   i actually cheat on this..  as i pull the head and do a valve job and as i posted in my first reply.. grind the valve faces or stems to fit the existing shim discs.. but then i have  a Sioux valve seat grinding set and a matching valve refacer...  not something the average mechanic has..


pick up a package  of 30 eggs..   you can use the egg crates that come with it to sort the valve discs...

mark the cavities in the egg trays for the discs...

measure the valve adjustments of EVERY valve and write it down..  

pull the cams...   remove the valve discs  with a magnetic tool...   place them in the EXACT marked cavity in the egg tray..   once you get them all out..   you will want to clean and measure them... mark them with a sharpie..

write the sizes removed on the chart with the valve clearance...  with some math.. you can calculate how much thinner you are going to need...   write that number down on the chart also...

start another chart..   with the list of the valve discs you need...  and a second column with the valve discs you have...    see if there is any way to mix them around to get the valve clearances you need..    what you have left is what you need to buy..   either from mazda parts.. from goodson.. from a mazda mechanic..  a rebuilder. but they don't really sell their valve shims.. they use them a lot.. but different shops are different..

i don't know off the top of my head what size your valve discs are in diameter..


25mm Valve Clearance Discs
27.0mm Valve Clearance Discs
27.5mm Valve Clearance Discs
28mm Valve Clearance Discs
31mm Valve Clearance Discs
34mm Valve Clearance Discs
37mm Valve Clearance Discs

each of the discs has its own range of thicknesses available..    if you have worn valve seats.. or worn valve faces.. you might not be able to get a thin enough disc to work as the valve is sitting too deep in the head...