i need help BAD

[RigsLS]

Probably Cats

Catalytic Converters. They get damaged and clogged by misfires if you let it go too long...

First thing I thought of when reading the OP's statement of issues as well.

As Joe explained, CATS are clogged from prolonged misfiring, restricted flow is the end result thus stalling out under load.

~ rotten egg smell.

 

[RigsLS]

I am having the same problem, if i floor the car, the RPMs cut down and the car doesn't go anywhere...


are your roads icey too?

 

[Telco]

First thing I thought of when reading the OP's statement of issues as well.

As Joe explained, CATS are clogged from prolonged misfiring, restricted flow is the end result thus stalling out under load.

~ rotten egg smell.

Nah, I don't think so. I've had one or two with clogged cats. A clogged exhaust won't build the RPMs. It'll get that deep sound that you get when you're pulling a heavy load and the RPMs are way low, and you go WOT, but it'll take forever to build the RPMs and will never have power. It's simple enough to check though, start the car and feel the exhaust coming out the end at idle. If you feel pulses, the cats are fine. If you feel a constant breeze, or if the pulses don't feel defined, there is an obstruction that is blocking the exhaust. The blockage will build pressure behind it which will smooth the pulses out.

Easing into the pedal and getting acceleration, but going WOT and getting a lot of high RPM noise and no go, sounds more like the trans is low on fluid. The TC lets go of the trans if it doesn't have enough fluid, and the engine goes hog wild. Light pedal acceleration means the trans pump is spinning slowly, heavy pedal means the trans pump is pumping the fluid out. Of course, it could also be a high pressure leak inside the trans or damaged fins inside the torque converter.

Since this is an LS though, step 1 is still to replace the COPs and plugs.

Oh, and

 

[lincolnelite]

I've read somewhere (from a Ford tech, not on this forum) that it's seldom for LS cats to go bad when the COPs fail because the PCM was designed to not dump fuel when the COP is not firing. So the most noticeable issue is losing power (or not gaining) during throttle. It could still happen but less likely, at least Ford engineers somehow got this right..

 

[chris2523]

I've read somewhere (from a Ford tech, not on this forum) that it's seldom for LS cats to go bad when the COPs fail because the PCM was designed to not dump fuel when the COP is not firing. So the most noticeable issue is losing power (or not gaining) during throttle. It could still happen but less likely, at least Ford engineers somehow got this right..

uh nope. plenty of LS's with bad cats from bad COPs.

 

[LS4me]

uh nope. plenty of LS's with bad cats from bad COPs.

Ummmm.... YUP!!!!!

 

[joegr]

I've read somewhere (from a Ford tech, not on this forum) that it's seldom for LS cats to go bad when the COPs fail because the PCM was designed to not dump fuel when the COP is not firing. So the most noticeable issue is losing power (or not gaining) during throttle. It could still happen but less likely, at least Ford engineers somehow got this right..

And, this works for the somewhat rare case when a COP fails completely. Unfortunately, they most frequently just become marginal. When marginal, it may fire four times out or five (or one time out of five), and apparently that is enough to keep the PCM from shutting down that cylinder.

 

[1LoudLS]

I've read somewhere (from a Ford tech, not on this forum) that it's seldom for LS cats to go bad when the COPs fail because the PCM was designed to not dump fuel when the COP is not firing. So the most noticeable issue is losing power (or not gaining) during throttle. It could still happen but less likely, at least Ford engineers somehow got this right..

as joe pointed out, LS coils rarely ever fully fail to the point where the PCM shuts the fuel off.



both of my LSs have had damaged cats from misfires.

with my first LS, I was picking it up from the ford body shop after a lady ran a red light and blew the front end off... anyway when picking it up it was running kinda rough, they told me it ran perfect when they test drove it before calling me and it might just be a bit of bad gas from it sitting getting worked on for a month and just drive it and it will clear itself out. well turns out they power washed the motor (V6) right as i got there, well water got down in the plug wells and was causing a bad misfire, bad enough for the PCM to recognize this and give me a flashing CEL with in a mile, drove it back to the shop and left it. long story short they had to replace the cat because they were fukced.

second LS just had a couple of coils that would rarely ever misfire, well one day that rare misfire developed into a full on failure, had to limp the car the last mile to the shop where i could work on it. same thing, bad misfire caused a clogged cat...

both of these misfires were pretty major and neither one of them caused the computer to stop throwing fuel in there.

 

[lincolnelite]

so it's still a stupid design... what does the ford tech know..