What can I expect a Mazda dealer to tell me about my cars issues?
 

So the other day I was driving home and my car died on me. It started misfiring and as soon as I clutched in the car dropped to zero. It wouldn't bump start or turn over. Cranks for days at ~300 rpm but won't turn over. Checked my codes and got an o2 code from my punched cat, a misfire code on both rotors, and a lean code on bank 1 sensor. Maf is clean, plugs are fresh, oil is low but not empty, Filters are clean, coolant good, no smoke, no clanking.

I had it towed to the dealer for them to check it out under warranty but what can I expect them to tell me? Fuel pump, coils, compression? They don't want to run a compression test as part of their diagnostics until the very end, but I plan on insisting on one. My issue is the lean code, the only vaccum hose I have issues with is my vfad and that is from the previous owner breaking the solenoid. I have that line plugged at the throttle body so it shouldn't be that causing my issue.

Does a lean code with the 2 misfire codes mean I blew something up in my engine or is it just my ignition/ fuel system not being up to par? Or is it more likely just an air leak issue, although I can't find any discernable leak location.

misfires are 99% of the time ignition related.

+1^
Also, as a result, misfires kill cats, and if the ignition components are replaced, the bad cat can cause misfires afterwards.
The cat should be inspected in conjunction with ignition replacement.

Turns out so far they found 3 dead coils and 2 bad plugs. Weird cuz they are only 20k miles old and I thought the OEM was rated for 35 but ah well. They quoted me about 650$ to change out all 4 coils and wires, is that stupid high or to be expected?

Oh an on a side note, would the misfire or the ignition problem cause the lean code or is that going o be a secondary issue?

With 2 of the dead coils being on the same rotor, the lean condition comes from there not being any ignition in the first place, so all the oxygen it sucks in goes right out the tail pipe.. so the O2 sensor sees lean condition.

650 is high, if you have basic tools and half an hour, you can replace the coils and wires yourself. AutoZone or similar should have them for about half that.

Hell just a simple search popped em up on Amazon OEM for 50$ for all 4 so ya. You think dealer would be mad if I replaced em in their parking lot to avoid paying them? And if there was no ignition I would think it would run rich since it would detect all the fuel leaving the tailpipe. Also having a gutted catalytic converter I'm not sure that o2 sensor picks up much of anything lol.

I can't say if they'll be mad, but do look out for cheap knockoff coils from eBay and Amazon. You're better spending a bit more at an actual store, especially since AutoZone carries a lifetime warranty, I believe.

The oxygen sensor doesn't detect fuel, it detects ..oxygen.

Hmm I'm still not used to Amazon allowing third party sellers. Are the coils sold at AutoZone even decent? I've heard bad things about some duralast parts in the past but they do indeed have a lifetime warranty. And they are 25 a piece so not too outrageous.

+1 on avoiding eBay & Amazon.
I've bought some lifetimes from Advance, you can also get online coupon discounts.

I wouldn't change the coils in the dealer's parking lot. I suppose you could but to avoid confrontation with a dealer you may use in the future, I'd just say no thank you and tow the car home and do it there.

My question is if the car is under warranty, why would they give you a quote of $650 for parts and labor?

Well they only have one service manager there and she straight up told me if I pay her the 120$ diagnostic fee they will roll the car wherever I like and I can swap em out there. If the problem isn't fixed they will roll it back in and redo the diagnostics. So it isn't going to cause any issues according to their service manager.

As for the warranty, the coils are considered part of the maintenance or tune up schedule so that isn't covered under my warranty, hence parts and labor for the coils I was quoted 650. It's not the factory warranty, it's one that transfered from another bank when I bought the car.

If you are even remotely mechanically inclined, you can DIY & save good money even after a tow bill.
Your insurance might cover the tow.

Oh I'm going to save money over what they want. I already had it towed to the shop as I feared the worst and if I had a blown engine I don't have the tools to take care of it myself. My insurance won't tow it back to my house or anywhere else as long as the dealer is willing to do the work.

I'm going to do the job myself myself and save about 50% of what they are asking lol. It's just 10 mm bolts holding the coils down under the airbox lol

Changed out my coils and still no start. I smell a lot of fuel though so I think they may have flooded it when diagnosing or just as a result of the coils dying. Will try to bump start tonight after the roads clear out and will update accordingly.

A question because it just occured to me. There have been 2 instances in the past month of my car belching out white smoke to the point of James Bond smoke screen. I thought it was just water build up in my gutted cat being evaporated off. It also ran like absolute dog crap lol. Could it have been unburned fuel rather than condensation? IE my coils weren't firing and it was causing excess amounts of unburned fuel to come out the tailpipe?

Yeah 3 failed coils would do that.

If you think it is flooded, perform the de-flood procedure. IIRC, it consists of simply holding the gas pedal to the floor to cut off fuel and cranking the starter for several revolutions. Lift off the gas and start as usual.

The thing is I tried this to the point the battery started waning and still smell straight fuel. And idk if I have another car willing to sit there and idle for an hr while I crank with no fuel.

Are you absolutely sure you got the sequence right from the coils to the plugs?

100%. I replaced em 1 at a time so there was no way to mix it up

Are the coils wires connected tightly (snapped /clicked into place)? Have you pulled the plugs to see if they're wet with fuel?
It's best to have a way to charge your battery. Your engine could be severely flooded, so it will take a number of attempts to fire up, thus draining the battery.

+1^
A weak battery will cause flooding.
​​​If you're not sure it's 100%, and don't have a way to boost it, you might try borrowing a good battery.
My last flood was from a weak battery that was only 3 yrs old.
If it's an older battery, you might consider getting a new one.

Alright alright alright ladies and gents. Got it de flooded and running and issues galore :(. It refuses to stay idling, I'd imagine that might be it learning it's fuel trims. It drives nicer than it ever has before, but after 15 miles the CEL came on for a p2096 lean code. The misfire codes are gone so I don't think this is a remnant. I looked through the forum's but just wanted to verify my trouble shooting.

I'm probably going to pull the plugs and give them a nice cleaning even though that are less than 100miles. I'm going to clean the maf and check all the filters. What else can I check? I didn't have an air leak before I don't think. The only thing that kind of changed was I got a slightly larger screw for my maf as the old ones stripped out their threads. The new ones are same length though and marginally bgger so I don't think that is the cause. Any other directions I should be checking? A gutted cat wouldn't cause this code right?

Gutted cat shouldn't cause that code.
If you clean your plugs, use a soft bristle brush so you don't damage the iridium coating.
Dirty MAF can cause it, the screws shouldn't be an issue if your O-ring is seated properly.
Check your vacuum lines in case you accidentally knocked one off.
If you have a handheld propane torch, you can go around the connections to check for leaks.