Highly recommend stock OEM plugs, not aftermarket.

 

I had a similar problem with my G once and it was the fuel pump. Wouldn't hurt to test. Also can be the clogged cats you mention but they are more prone to a loss of power rather than a no start.

 

He's already smelling the rotten egg odor so the cat is guaranteed bad. Logical first step and proceed from there. I've seen a LOT of different malfunctions from a bad cat not just loss of power. Sometimes it's random codes being thrown sometimes it's catastrophic meltdown failure and a vehicle dead in the road.

Edit: One time I even got the displeasure of driving closely (probably too close) behind a vehicle as the cat went volcanic and I drove over the slag and ruined a good tire...

 

As someone who's mechanical ability is limited to replacing an air filter, battery or spark plug that build is quite something. Always envious of people who are mechanically gifted cause I am terrible, Some people here probably got a bit uptight from your title, especially when you don't know how it was treated the previous 150,000 miles lol. As stated, OEM sensors and also make sure you've done all the ECU and throttle and idle relearns properly, easy to go wrong doing this.

 

Yeah it usually takes me about 2-3 tries to get the pedal dance to work, using a clock with seconds counting is a MUST.

Something else I just thought about Reckless, go through all the engine bay grounds and brush them, apply oxidation inhibitor, just a good preventative measure against bad things happening like ECU getting wrong data from sensors due to resistance on the ground wire and delivering the wrong amount of fuel. There's 8 ground points (battery counts as one) for a 6MT, 9 if AT (counting the two for the headlights).

 

Looks like we're gonna have to wait to see if the cat delete fixes the problem. Only reason I ask about the plugs is cuz I once had a truck that would stall now and then because of a small head gasket leak that would leave calcium deposits (as the coolant was dried) in the plug gap and keep it would literally keep it from firing. Take it out, brush it off with a wire brush and it would go again. So, I was getting spark from the coil, but it couldn't be delivered to the cylinder. Very strange, and unlikely in any other case, but since then it's always the first thing I check. Haha

If theres a chance that they're 150k mile plugs tho, defs need to be changed. I know the fsm says 105k mile intervals but that should really be more like 60k, so I get NGK laser Platinums and do em every 40k.

 

Out with the old, and in with the new... I must say, this has been the easiest cats removal I've ever done. Now I just have to install the delete pipes and change the cam sensors to the oem ones.

I might cut up the old cats and take a look inside.

Hopefully I'll be loving the car again in a few.

 

From my experience, by the time it gets bad enough to be affecting performance you can just LOOK in the ends of the cat with a flashlight and see the melted spots.

 

Well.... back to the drawing board.

Replaced the cats, and installed all new oem sensors. Idles at 650rpm now, which it idled at 1100 rpm before. Not throwing any codes at all. Fuel trim went down 7-9%, so it's not running rich anymore.

But still won't turn over when it's hot, and once it's hot, if I rev it when the rpms drop down, it's still stalls.

 

Sounds like a closed loop O2 sensor problem, since the engine doesn't account for that data until they're up to temp.

 

If they engine won't crank when it's hot that's probably the starter, or corroded wiring.

 

I'm going to replace them, the upstream 02 sensors were staying .295V constantly. Not jumping around like it should be.

Downstream were staying between .650- .870V . Not really sure if I should change them yet.

Car crank fine, regardless if it's hot or cold, so it's not a starter issue.

 

i think people keep suggesting starter as a lot of people use "turn over" as the act of moving the engine with the starter not firing the engine over with fuel and spark.

Have you tried checking the throttle body position sensor and the pedal drive by wire throttle position sensor while hot?

 

My dad has been a mechanic for 30+ years, and growing up I've used "cranking" as the starter moving the flywheel, and "turn over" is the car actually starting and running. I guess people use the terminology differently.

I haven't checked the tps or pedal sensor since I'm not getting any codes for it , but ill check it and verify.

 

I would verify proper operation of the cam and crank phase sensors. If the ECU doesn't see them it will not open injectors or fire the coil packs.