My r53 will crank but won't start :( HELP
 

Hey everyone, I have a 2006 Mcs r53, I was installing a new exhaust, after the install I took it for a drive and suddenly the cat got separated in half. I didn't have a clue what caused the problem (broken lower engine mount) so I kept driving it till the next day, where I was on my way to an exhaust shop to get it welded back on, then the rpms started dropping slowly with no reaction to throttle till it eventually stopped running. Towed to my mechanic (where i found out that mount was broken and i felt like an idiot) and my mechanic told me it might be either the cam sensor or timing might've jumped a tooth. Ordered new sensor, took a look at timing and it was fine. sensor didn't solve the problem, now i have no clue what to do. Help please? is my ECU fried or something? Is it done? :((
Here are the codes:
-p0340 camshaft sensor issue
-p0037 o2 sensor heater
control sensor 2
-p0031 o2 sensor heater
control sensor 1
-p0445 purge control valve
system short circuited

My mechanic said (The vehicle is getting spark, but the injector pulse signal is not being sent, the vehicle is putting fuel up to the fuel rail, so there has to be an issue in the wiring, causing something to short circuit, or the eco is fried.)


Thanks everyone.

Damn, well first check for any burnt wiring.

How bad was the break at the cat ? Or was it just a crack at the flex joint ?

If completely separated at down pipe just below PS tank and coolant tank that's a lot of melting temperature heat being directed into the engine compartment... that could have messed up a bunch of electrical stuff under the hood too.....

https://cimg7.ibsrv.net/gimg/www.nor...02720dfdd1.png
It completely separated from the cat to the pipe connected to it, that's what i'm thinking. too much heat esp that i've been driving for about 40 mins on the highway so i might've ****ed up bad.

Was the ECU reset since the trouble? I am thinking that Helix has a video that shows you how to do this. You went from limp mode to lump of coal mode.

If the ECU was fried, I would think you get nothing out of it but you are getting some functions. What about the engine immoblizer, could it be causing the issue>

Good luck

When the exhaust broke, it may have broken one or more of the two Ox sensor wires in either the upstream, or downstream. These need to be repaired, if they are broken, before you will ave any chance of your car firing.
When you have it welded up, those wires need to be checked.
Keep us posted and when that is done, let us know how it is doing!

hi, I have a r53 (2005 s) header taken off at 79k... passed MA inspection just before I installed a Milltek header... let me know if interest

My header broke the same way and I drove it for about 4 months like that and it didn't hurt anything. Except my ears and my power output.

If the honeycomb core of the cat is clogged or melted, your car will not run or start.

Yeah i thought about that, asked my mechanic to check it and he said that the cat isn't clogged, he tried cranking it and air was still coming through the exhaust

So you're saying that if i reset the ECU it may start back up?

Probably due to my broken engine mount, something was loose

Fuse

Check the fuse for ecu in the engine bay. We have like 3 of them. This happened to me. Fuse popped all the same codes. My O2 grounded to the chassis. Wire split and hit the chassis caused the ecu fuse to pop. Let me know how it goes. FYI tell your mechanic the first step is to check fuses and not timing lol.

Will do. I will check the fuses asap.

PLEASE tell me that this exact same thing happened to you???

Update: Checked the fuse, all fine. :((

Ground for Engine ?
 

Maybe check the ground strap for engine on pass side front near hydraulic engine mount. See if tight, still attached.

If you have to re-attach/tighten, don't use anything larger than a 1/8 in drive ratchet with socket. It is very easy to break off that stud when tightening that bolt.

https://cdn4.pelicanparts.com/techar...mall/pic03.jpg