Cat convert. blew out check engine light, PO171 too lean.!!!

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Jerry Gerner 2

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Hey guys, ok so I installed the SD coil pack, Live Wires, Autolite APP 103's, fuel filter like suggested. Later that day the check engine light comes on, I go to Advanced, code 171 too lean, after I leave there the Cat starts breaking apart and truck lags. So I replace the PCV Valve, clear the codes and runs fine for a day. I was on the highway doing 60 climbing a mountain and the truck starts to lag again, give alittle more gas and the check engine light starts flashing, get over the mountain and the light goes out, mile down the road lights back on solid and truck really lagging. WTH??? I know I need to replace the Cat, do I need to replace the O2 sensors now too??? What else could be wrong?? Please help!!! :cry::banghead::banghead:
 
Did you replace the rubber elbow or just the pcv valve? Which cat came apart? One of the light ups or the main cats? Unless some of the brick material hit and damage the O2, Probably ok.
 
I already replaced the elbows and line. Not sure which Cat it is that has stuff jingling around in it, either the front or rear, haven't taken them off yet. I was thinking about taking the Y-pipe off, cutting off those two cats and replacing them with exhaust pipe welded in. Taking the front main cat off checking it and replacing the rear cat with exhaust pipe (pretty much the poor man's RT exhaust). Will the O2 throw the PO171, all of this started after I installed the SD coil, Live Wires, and plugs (Autolites APP103's gapped at 54) could I have a bad wire, coil, plugs??? I'm not familar with newer emmission controlled vehicles, used to working on old musclecars. How can I check to see if the O2 is bad, how many are there and how much do they cost??:angry::angry::banghead::banghead::cry::cry:
 
Put your original coil on and ses what happens. I have seen the 171 / 174 code come on with the installation of the SD coil.



As mentioned, the 171 / 174 code is normally the elbow, but if you have replaced it, and assuming it is all connected still, then swap the coil out to see if the code will remain off once cleared.
 
First, anything is possible. That said, it is not probable...



I believe you are going to find that the code you are throwing is a true/legit fuel to lean error. The O2 is coming back with the code as it is in fact seeing to much air in the air to fuel ratio. My next suggestion will be the upper intake gasket, which is testable using propane.



As I said, I have seen the SD coil pack throw this code but MOSTLY with Job 1 applications. I just feel you need to get to "base" engine application before you do too many things. You can always throw it back on if the code comes back...



 
Put your original coil on and ses what happens. I have seen the 171 / 174 code come on with the installation of the SD coil.
Click to expand...



+1 to what Coastiejoe said. I've had two SD coil packs go bad, and they threw those CEL codes. Put the OEM coil back on and drive her for a while and see if the codes return. If not, the SD coil's bad.
 
Swapped the cool back to stock drove it all over, let it idle for 30 minutes and no code/ light. So I'm gonna contact George about returning the coil and stick with stock. Thanks again for the help, I was getting irritated.
 
Jerry my drivers side front cat broke up and clogged up my main cat. I hollowed them all out and have not had the check engine light come on, it's been 9 months now. It acted just like yours is lagging and then running fine for a while untill I tried to pull a pop up camper then the main converter plugged completly, that is when I hollowed them out. No inspections here in Michigan.
 
That's the problem with multiple cats, you don't know which one to replace without taking them all off. Like yours did one blew and screwed with the others, makes no sense other then money making scheme. :angry::banghead:
 
Jerry, I suggest you drive it with the OEM coil for a few days as it may take something specific that trips the code.



I say this as, if you get the SD replaced and the light comes back on, you will not know for sure the cause.



I would leave the OEM coil on for like a week which will give you all the range of driving applications that you would normally entertain.



Just my thoughts...
 
Ok, thanks. I stillneed to take off the y-pipe and cats to check which one is blown out before it causes any damage to the sensors and or the othe cats.
 
I bought a used SD coil. I have been worried about it. There have been many of them go bad on this board the last few months. I carry the stock coil with me.

I paid more, than used is worth and have no warranty. Actually wasted my $$.:banghead:

It would help more if the stock coil had more saturation time. Or multi-spark and a good set of spiral wound plug wires.
 

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