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I ran a torque diagnosis after picking the car up from dealership... I got 3 misfire on cylinder one from a 10 minute ride...
coils?
I also noticed that my cats o2 sensor had a glowing ring..does that mean the cat is blocked?
The glowing ring definitely means the cat is in bad shape, and is probably what killed the previous engine. Good on you catching that. So stop driving immediately and look up the laws in your area around returning used cars.
Coils, spark plugs and wires probably need to be done too, if they're old, they're what killed the cat.
It's really important to inspect cars -- any cars -- fully before money changes hands, for reasons like this.
Subbed. This is something I have observed as well with my fairly new(5500 miles/9000 km) OEM Revision C coils.
I have very low counts of misfires according to the misfire monitor on my OBD2 reader, like in single digits range just like OP. Not sure if this is a legitimate concern.
As for the glowing ring, it's hard to say. My factory cat was glowing after some hooning around(sustained 5k RPM) and I have inspected it. No blockage. If you are observing it during idling, however, I'd definitely take it off ASAP.
Last edited by UnknownJinX; 08-14-2018 at 10:37 PM.
I would not only replace the coils, but the plugs and wires as well. Take no chances with misfires, especially if you do not know the car's history. As far as the catalytic converter is concerned, I would return the car to the dealership and see if they will cover any of the repair costs of a replacement. Was there any warranty with the car at the time of purchase? Did you buy the car from a Mazda dealer and if not can you see the blue reman tag on the front cover and does the engine look new? If not, head over to your nearest Mazda dealer and have them run the vin to confirm a reman engine was in fact installed in the car. If you don't know the car's history, this is the least you can do. Don't take another dealer's word for it.
All of the advice given is sound and none should be ignored. I'd prioritize in the following way:
-Stop driving the car immediately to avoid engine damage
-Remove and inspect the factory catalytic converter for damage or blockage.
---Replace or de-cat if at all suspect of failure
-Replace the coils, plug wires, and spark plugs.
---Either go with Mazda 'C' Revision coils or an ACDelco D585 coil upgrade. Use OEM plugs (NGK). Use OEM wires (NGK/Mazda) if retaining OEM coils
-Perform an ESS (Eccentric Shaft Sensor) Re-Learn once the above has been validated.
----EDIT: Refer to NotAPreppie's comment below for Series II ESS Re-Learn proceedure
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-Perform an ESS (Eccentric Shaft Sensor) Re-Learn once the above has been validated.
----Turn the key to 'ON' but do not start the car or engage the starter. Quickly depress the back pedal immediately after Key-ON approx. 20 times. The oil pressure gauge will move to the middle position and then back down to the low position, indicating an ESS Re-learn has been initiated. You may then Key-OFF and Key-ON/Start the car and enter a drive cycle. You may get a ABS/DSC lights during the first drive cycle but they should clear up by the next drive-cycle.
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All of the advice given is sound and none should be ignored. I'd prioritize in the following way:
-Stop driving the car immediately to avoid engine damage
-Remove and inspect the factory catalytic converter for damage or blockage.
---Replace or de-cat if at all suspect of failure
-Replace the coils, plug wires, and spark plugs.
---Either go with Mazda 'C' Revision coils or an ACDelco D585 coil upgrade. Use OEM plugs (NGK). Use OEM wires (NGK/Mazda) if retaining OEM coils
-Perform an ESS (Eccentric Shaft Sensor) Re-Learn once the above has been validated.
----EDIT: Refer to NotAPreppie's comment below for Series II ESS Re-Learn proceedure
-
For reference, I did all of the stuff recommended.
Wires were replaced with the coils, and plugs were replaced just this spring.
I have a BHR mid-pipe and HJS high flow cat.
ESS was reset a while ago.
No drivability concerns, obviously. I pulled redline through the first 3 gears, no problem.
So I am not sure what it is. Perhaps it is just from the engine trying to learn when you just reset the ESS profiles?
The ESS profile should be relearned in under a second. It should only need one or two full revolutions of the crank to build a profile of the tone wheel.
How about the secondary air injection pump?
Were the fuel injectors tested for flow and confirmed to not be leaking?
How many miles on the upstream o2 sensor?
A glowing cat can indicate a lean burn condition or conversely, post-chamber combustion.
(sorry for hijacking the thread, but since I have a similar concern...)
IIRC secondary air injection doesn't do anything outside of cold starts, so it wouldn't affect cat performance when the car is hot.
I haven't checked my fuel system, but again, there is no driveability concern for me to tear the fuel injectors out to check them. I will probably do it when my engine bites the dust and the whole engine is torn out anyway, might even go for a ultrasonic treatment.
Front AFR was replaced a while ago with a Denso(which is OEM) unit.
It shouldn't, but I've seen smog pump motors fail into an ON-state, forcing additional air into the exhaust stream when it isn't wanted. It is rare, but still a possibility.