[superleggera20]

Hello All,
Just purchased an 08 superL, fun car so far. I used the DIY thread in this forum to learn a ton about these cars, their maintenance, the parts etc (been super helpful). I went ahead and got an LOC exhaust for the car as well. It needed and I did change the spark plugs, ignition coils, diff fluid, brake fluid, engine oil and of course LOC exhaust install.

Got a few CELs first it was just 6-10 now they're both on flashing 1-5, 6-10. Read all about the common exhaust issues with these very sensitive computers.

Got a generic Wifi obd scanner and used the Dash Command app based on the recommendations of this forum:

STORED CODES:
p0308: cylinder 8 misfire
P1426: Unknown diagnostic code

PENDING CODES:
p1306: UNKNOWN diagnostic code
P0301: cylinder 1 misfire detected
P0303: Cylinder 3 misfire detected

(i looked at the lambo codes and what correlates and know at least 1 of those unknown's is an exhaust code)

worth noting i had 00 lights before all of this work was performed. I have seen in the past an ignition coil being DOA but it will cause the car to run like a honda lawnmower. Never have i seen a bad coil throw codes for other unrelated coils not even in the same bank as the alleged culprit.

I have cleared the codes (with accessory on), will drive this weekend. Also when picked it up from the shop it ran well, was LOUD from the LOC, raw n viseral (normal SL shakes n boogies) but nothing that felt out of spec but then again I've had the car for 2 weeks and driven 30 miles totally stock before the work was done.

Will say my low speed turning wheel GROAN is gone due to the diff fluid (what a night and day difference)

Any ideas, suggestions or direction is greatly appreciated.

thanks in advance.

 

[monEmakindave]

First congrats on the SL!

Post some pics.

I also have read about the sensitivity of our cars I got a random 1-5 one time on my totally stock SL. Went away after a few miles and restarts. The computer just senses something out of the ordinary and it triggers it.

I’d also disconnect the battery for a few minutes so the car can re learn it’s new parameters with the new exhaust. Might be worth a try.

Just get some miles on the new mods. Many of the videos I’ve seen with modded SL’s all have CEL.

 

[superleggera20]

Drove the car 12 miles this morning, at 8miles in I had a yellow CAT 6-10 light on, this went off at a red light when I was turning around to return home, just prior to this felt as if powered fell flat (was being pulled), light went off, full power again (6-10 CEL on as well).

Pulling into garage I cleared codes and pending we had:

p1405 (catalyst at overtemp 1st level)
p1406 (" "" 2nd level)
p1426 (P1426 is showing Bank 1 cat temp sensor)

it would just between those and

p0307 (cylinder 7 misfire)
p0308 (cylinder 8 misfire, this is the original code)
p1426 unknown (P1426 is showing Bank 1 cat temp sensor)

This all looks like the brand new LOC exhaust that was installed....is that a fair assumption?

Titanium heat wrapping was used on the exhaust as per the DIY on this sites suggestion, also the car has/had 3/4 tank of VP Race Fuel (unleaded 106 or 109, don't remember)

Possible its a combination of super high test gas on a fussy ecu with a new exhaust burning all the new out of it , that's also heat wrapped with titanium ? Would an ECU tune resolve these issues?

 

[Jason B]

Yes, pretty much normal for a 2008, the ecu is more sensitive on last year pre LP. I have an ECU tune that will fix it for good, or can get you some o2 mini cats that would help get rid of it. Feel free to text or call me.

 

[superleggera20]

Jason just shot you a txt!

 

[superleggera20]

Worth noting, the CAT light was yellow during the ride and turned red before pulling into my garage, car has STOCK cats with 20k on them, brand new LOC exhaust w/titanium wrapping, new plugs, coils, and VP race fuel (unleaded)

 

[StoleIt]

Worth noting, the CAT light was yellow during the ride and turned red before pulling into my garage, car has STOCK cats with 20k on them, brand new LOC exhaust w/titanium wrapping, new plugs, coils, and VP race fuel (unleaded)

Do you have some sort of forced induction (turbos/supercharger)?

If not, stop running race fuel immediately. Just run 93.

 

[superleggera20]

Do you have some sort of forced induction (turbos/supercharger)?

If not, stop running race fuel immediately. Just run 93.

Thats what i am doing now, grabbed a bottle of fuel cleaner to hit injectors, etc (BK44) and am trying to slowly,safely drive down the gas level and continue to add 1-3 gallons a time of 93 to bring down the octane back to a safe parameter (if that is infact making the ecu trip_

 

[superleggera20]

Issue traced back to a disconnected wire in on the plugs going into the coils, 1 was not firing, not firing the plug, etc and you can see how it spiraled from there....replacing pin inside the plug and all should be good.

 

[StoleIt]

Noice! The rare cheap fix!

 

[superleggera20]

ALL FIXED!

LOC exhaust, NO CELS, NO CAT lights, NO LIMP MODE

6-10 was a bad connection on the plug connector, not firing the coil and plug which dumped fuel into the cat heating up the temp rapidly.

1-5 was a spark plug that's gap was WAY out of spec

I guess lesson learned, never let a blind mechanic work on your car ever again...end of the day I had to dig through mud before I finally found gold (which ended up being the right person to work on these cars).

Thanks everybody, forum was BEYOND helpful in a resolution here.