Help with emissions testing ( ECU ) sensors

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unwind
Posts: 1
Joined: Sun Mar 29, 2009 3:22 pm
Location: salt lake city

Help with emissions testing ( ECU ) sensors

Post by unwind »

I forgot to use my trickle charger my battery was completely dead. I purchased a new battery, my ECU lost all info for the sensors. I have driven the car, I have gone thru two tanks of gas. I have 2 sensors left to get enough info to pass emissions testing, both CAT sensors. no OBD2 codes. Any suggestions on how to get the sensors to show good for emissions test faster? Thanks'
2007 gt 6 speed black & tan, tokico hts adjustable, eiback pro, roadstersport 2, racing beat intake, beatrush towers.
CaseyM035
Posts: 2
Joined: Fri Apr 22, 2022 11:57 pm

Re: Help with emissions testing ( ECU ) sensors

Post by CaseyM035 »

This is what worked for some mazdaspeeds from around your year, guessing the emissions cycle is similar. Give it a try if yours isn't ready now.

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MarkP066
Posts: 3
Joined: Fri Jul 01, 2022 6:55 am

Re: Help with emissions testing ( ECU ) sensors

Post by MarkP066 »

replying to an old post but this might help someone in the future. All other manufacturers cars I have worked on have the same test conditions so I dont see why Mazda would be any different.

In order for certain evap monitors to run the car has to be in a test position. The fuel tank should be between
1/4 and 3/4 full and in my experience the evap monitor wont run if the fuel in the tank is above or below this.

The car has to be cold. The PCM (powertrain control module) determines “cold” by the difference between the ECT (engine coolant temp sensor) and the IAT (intake air temp sensor). This difference should be no more than 10* and the engine has been off for 8 hours or more.

Most manufacturers require this test to be done twice, this is what is referred to as a 2 trip test.

getting any specific information from any manufacturer about the what, when, why and how is next to impossible, they just keep referring you to that year, make and model “Drive Cycle” which is referenced above.

Even after all of this there are certain cars that are just impossible to smog. The BAR (Bureau of Automotive Repair) knows about these vehicles and has made modifications to the smog machine software to help in getting these vehicles to pass the test. The list is on the BAR’s website but you have to search for it.

even after all of this you still have to rely on the smog tech who in my experience, just doesn’t care.
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