PMCSPIDER

iTrader: (1)

I am running flashing SES codes: 0305 & 0704

I have replace all wires, plugs, fluids and filters, and nothing.

I am familiar with Ford 4.6L & 5.4L engine maintenance, I used to have a '93 Z71, but that doesnt help me with general maintenance with my LS1. As embarrasing as it is, can someonw please give me some pointers as to how I go about doing the following?:

SES Code 0305 - I have a replacement coil, and dont know where to start on replacing it.

SES Code 0704 - Do I need to replace the O2 sensors? Specifically the front two? Would cleaning the MAF help too? How do you replace these? Do you need a special tool to swap them out?

Regarding the LS1 firing order, if I am correct, the 5th cylinder is teh second to last row on the driver side...am I right on this?

Thanks in advance for any pointers.

BlackScreaminMachine

iTrader: (17)

If your trying to determine the faulty coil, get a plug checker, its like a spark plug but it will show the spark trying to cross the gap. My mechanic buddy had one.

When looking at a cyl order of a LSX or even LTX, from the front of the motor, moving back ward its Even #'s in the right (passanger side) and Odd on the left(driver side). # 5 would be the 2nd to last cyl.

I would replace all o2 sensors and not mess aroound, they are cheap and should elminate alot of questions. Thats if they have alot of miles on them. Also take a can of brake clean and get the contact filiments. Just dont touch them.

As for the sensors, on my 2 off the cats were like welded, the after cats were fine. They do sell a slotted specific o2 socket.

PMCSPIDER

iTrader: (1)

Do you recommend a particular brand of O2 sensor? or just the basic Bosch O2 sensor? Again, a dumb question...do you ned any specialty tools to replace the O2 sensors? How long should it take a "mechanic" to do it? Do you normally have to remove any other engine components to get to O2 sensors? I would normally get guidance form my brother "SHINER" but he is offshore. In an email, he suggested that I need to replace my cat (its bad) and go with a Y-pipe and get new O2 sensors. I currenlty have Edelbrock shorties with a 40 series Flowmaster muffler. Thanks again for any help.

2001NBMZ28

Why do you want to replace the 02 sensors? P0704 is Clutch Switch Input Circuit. Before replacing the coil on #5 I'd switch that plug wire with an adjacent one, along with pulling that plug to see what it looks like and see if the code moves - might not be the coil at all. If a cat was bad I'd think it would be throwing P0420 or P0430 depending on which bank.

PMCSPIDER

iTrader: (1)

My mistake, it is not a P0704 DTC code, it is a P0407 code. My brother (SHINER) thinks its a bad cat, and suggested that I replace the entire sytem (including my Edelbrock shorties w/ LT's)...sounds very necassary. I got new MDS plug wires in the mail, and two new Bosch O2 sensors..yeah they need to be replaced too.

As far as Cylinder #5, I noticed that right above the plug wire set connection there was some dried burnt-looking fluid (brownish-black...almost like burnt oil) What would this indicate?

Can I simply remove the cat all together? I know it woudlnt be very quiet per say, or pass emissions but the HP would go up and the code would solved possibly.

Thanks in advance for the pointers guys.

99345hp

If you remove the cats, you will need to get O2 simulators for the rear o2s or have them tuned out of the computer. I'm not sure what the burnt fluid would be, unless it was stuff from inside the coil. Instead of changing the plug and wire around, I would switch the coil from #5 with #1. Then if the misfire changes to #1 then it will be easier to change the coil. If it doesn't change, then you also have to look at an injector failing. Does the car miss really bad at idle? If it does you can listen to the motor and unplug the coil, if it changes, then its not the coil. Try this with the injector too, if it doesn't change, then its the injector. If one or the other is completely dead, then this test wont work, because the cylinder will be dead.

PMCSPIDER

iTrader: (1)

To be honest, it feels like it is going to have a heart attack and die of lung cancer at the same time. It is awful dude. The only reason I suggested the O2 swap, is b/c afte rpicking it up from the shop and having the plugs, filters and fluids changed, he told me that the O2 sensors were reall bad, and needed to be replaced. If I switch the plug wires, the O2 sensors, and seafoam the **** outta the engine...I am hoping to get a "night and day" effect on performance. The cat business, I will wait. But I like the idea of no Cat, and O2 sims.