So I m opening this new thread in reference to previous one..

car is running kind of rough idle and getting " restricted performance " off and on plus check engine light coming on .. so I was able to pull codes using Icarsoft 1930

P0174 system too lean bank 2
P0300 Random multiple cylinder misfire detected
P0301 cylinder 1 misfire detected
p0303 cylinder 3 misfire detected
P1316 misfire rate above limit
P0174 system too lean bank 2
P1000 the fault code is not found in the databse

 

How many miles are on the car and do you know its service history? Tune ups, as a starting point, tend to be expansive as the manifolding must be removed to access the RH cylinder bank (#s 1,3 and 5); it is often prudent to replace the plugs, coil-packs and valve cover gaskets while the manifolding is removed. OEM quality parts are strongly recommended.

 

Okay, making some progress! What did you do to get your scanner to work? In your previous thread, it was having connection issues.

For the present faults, I’d concentrate on misfire codes P0301 and P0303. In case you haven’t heard my famous speech yet, in OBD speak, a misfire only means low power output from a particular cylinder. The most common cause is ignition, but it could also be a bad injector, low compression, etc. Don’t let that scare you, but do keep this in mind in case the ignition checks okay.

Also, don’t be alarmed by the volume of codes present. The primary faults are the low power (misfire) from cylinders 1 and 3. The other codes are secondary, likely caused by the primary faults.

I would start by inspecting the #1 and #3 coils. On later V6 engines, these are the front and middle cylinders on the US passenger side.

Since the faults are on adjacent cylinders, I’ll bet you will find oil in the spark plug wells. This prevents the coils from firing properly. If you do find oil here, you’ll need to replace the valve cover gaskets. This is a common problem.

If no oil is present, inspect the spark plugs. Replace them if there is any doubt. Then swap the coils with known-good ones from other cylinders. Keep track of where you move them. Clear the codes and test run the engine. If the faults follow the coils, you’ll know they are bad. If the faults stay the same, you’ll know it’s something specific to those cylinders.

 

a bit of history on the work I did:

previously had blown head gasket so I removed heads had them done by specialty shop,


- reinstalled heads closely following all SFM instructions
- all seals replaced at plenum ,
- injectors o rings replaced and other
- new ignition coils (*ebay purchase may have been BAD idea )
- new spark plugs , timing chains with tensioner
- new engine oil pan gasket , transmission oil replaced
- valve cover gaskets
- water pump
- other seals at back of top plenum " sorry cant quite remember the name of sensors " oh yea IMT O rings/seals

Car does feel with power as I drive at higher speed …...

debating whether I should also do the o2 sensors ??

as always kr98664 great advise I will start by removing those cylinders 1,3 spark plugs and swapping the coils too ..

 

No name coils from eBay? May have been a bad idea? Change “may” to ”absolutely positively definitely beyond the shadow of a doubt”.

On the bright side, that may have been the biggest mistake you’ll ever make. You’d have to try really hard to top that one. You can rest easy now, knowing you’ve already reached the peak. Any future mistakes will pale by comparison. This doesn’t mean you can act with impunity. You’ll still have to apply reasonable efforts to avoid mistakes, so don’t marry a stripper, for example.

Forget swapping the coils for troubleshooting. I didn’t know the history when I suggested that. Order a complete set of a quality name brand.

Next, did a deep hole in your back yard. Don’t stop digging until you smell sulphur and brimstone. Drop the eBay coils in the hole and backfill the dirt. Wash your hands and walk away from them.

The O2 sensors? Hold off on replacing them for now. Whenever possible, don’t do too much at the same time. If changed at the same time as the new non-eBay coils, and then a new problem crops up, where would you start looking?

 

dude ! you're awesome man that is so funny......laughing my butt off with my son here ..
how about just replacing the three coils on the side and any suggestions where to get them ?
I did removed cylinder 1 looks good no oil or water found ! (haven't quite remove the wipers arm yet to completely remove the whole plenum to get to #3 cylinder so need to get a puller from autozone )

 

The other three coils are easy to access, right? That's how it is on my '02. If any of those coils act up in the future, it would be easy enough to replace them then.

I've got a mix of NAPA Premium and Beck/Arnley coils on my car. Any reputable name brand such as Delphi, NGK, Denso, should be fine. I'd avoid store brands from discount chains. For all we know, they came from the same source as those eBay specials.

Look on RockAuto for some options:

https://www.rockauto.com/en/catalog/...tion+coil,7060


Here's a dirty little secret about me, proof of my despicable nature. I'll often research part numbers at RockAuto, but order via Amazon for faster delivery.

If you're in a hurry and want to pick them up locally, I'm very partial to NAPA. Go with their premium line, as unfortunately they sometimes offer low cost options to compete with the discount chains.

 

since i gotten pretty decent stuff from rockauto before , I ordered all six of them earlier today i got the following :
UNITED MOTOR PRODUCTS COP260 United Premium OEM replacement COP coil Info
Coil on Plug
thanks for sharing your secret i might try that next time !
I m Not in a tremendous rush i like to get it running good , im getting lots of complements how the car looks from the outside so its worth it
any help i can get to atract a nice looking woman its worth it Haha.. sorry been offline for a while after second divorce ..

im also thinking about removing all dour 02 sensors cleaning them and put them back .. your thoughts on that ?

 

Please see my previous comments. One crisis at a time.

I’ve suggested replacing the coils because eBay cheapies are a known problem. Stick to one thing: replacing those and see what happens.

There’s a slim chance one of this next batch is also defective. Or because you’ve got to disassemble so much stuff for access, maybe something doesn’t get put back together correctly. Whatever happens, there’s always a chance of inadvertently causing a new problem. Don’t go adding new variables into the equation.

 

You say that, Karl....but there is that one member here who admitted to dumping a bottle of the special Jaguar "stop my steering wheel from squeaking" magic elixir into his brake system.........and was hip-deep into replacing EVERY non-metallic part in his brake system at the time of self-reporting....I say this to encourage the OP, yes! You can always beat the record! A set of bum coils is just training wheels stuff...

OP, I recently battled a bout of such codes (well, I'll see your P0300, P0301 and P0303 and raise you a P0305, P0302, P0304, and P0306! Strangely, although I had the P0174, no accompanying P0171?!? Think I also had the odd P14something or another indicating catalyst-damaging misfires - even though it all originated with a P0174 and P0306.
I renewed all six coils and plugs, as well as the cam-cover gaskets (must have done a bad job on that only a year or so ago, as I had some oil in a few plug-wells) and after clearing codes and executing a test-drive, had the P0306 back. Ah well, probably got a bad new coil - Mine were from Amazon...don't recall the brand but could look it up. Anywhoo.....turned it back over to my daughter for her 5 mi one-way school commute.

One cold morning she called and asked, "Where are the keys to Goldie? Peyton is shaking and the check engine light is flashing....."
"In my pocket; Goldie is nestled safely in the Bell Car Park out my window....you can't drive Blackie b/c the seat will go forward but not back, therefore I'll never be able to get in it again, let alone drive it! Call your bro. and see if he'll come take you to school and I'll leave you Goldie the rest of the week and take another crack at Peyton."

A code check when I got home revealed all the same suspects present as before my excellent mechanic-in' works! I called Bob (Motorcarman) and reported the above-mentioned renewals and subsequent sad results. He suggested it may be due to dribbly injectors. Not relishing R&R on all the injectors, and having a box of four (4) bottles of BG Products 44K handy, I noted "Peyton" being about half full of petrol, Observed a bottle was supposedly good to treat 20 (US)gallons. Having previously made great strides with a troublesome P0171/P0174 combo on the 2005 3.0L with BG 44K, I dumped a bottle in. No real improvement over the next few days, although no flashing MiL at least. Further conversations with Bob revealed in former times he had utilized a converted A/C flush tool, to inject a VERY rich mixture of Petrol/BG-44k into the injectors so I began contemplating same. Before I assembled the appropriate tooling, I was down to less than 1/8 full with the 8-9 gals petrol/1 bottle mixture. Having 3 more, I dumped in another one. Drove it close to the edge. Then, the wife turned her Toyota over to a detailer for the day and needed transportation to school. "Awight....dangit...I wanted more time on the rich mixture....and I think it's got plenty to get you to school and back (She's a teacher, I'm not married to a young co-ed) but if you're scared, put some petrol in it, but don't top-up, no more than 3 gallons!"

Of course she diluted my mixture. Nonetheless, the next several sequences produced no misfire codes, only the Bank 2 catalyst damage, P1420 (or is it P0420?) whatever.

With very little more drive time, I had to send that one off to School with kid #4 - Stephenville, TX, about 95 mi / 1.8 hours away. I cleared codes and attached an OBDII BT Adapter and told him to expect a recurring check engine light, but likely only the catalyst code. Got it back last week and had a host of misfire codes in "Historical" meaning they haven't been seen lately.....but the catalyst code is happy to return. We don't participate in those silly emissions games here in Wise co, so I'll research the forum here until I find the thread on the device that screws in place of the 02 sensor and satisfies the ECM...as the car performs flawlessly despite whatever ailment may be tormenting the #2 cat.

May be worth a try if coils don't do it, and you determine the injectors may be contributory.

 

Remember to check the vacuum elbow for damage when you take off the manifold while doing the coils.

 

​​​​​​Just wanted to say i bought 8 coils for my str when 4 OEM ones were bad.....85 dollars delivered.....straight from manufacturer....3 yrs ago.....still going strong.....maybe the exception, but i i spoke directly to them and was impressed by their knowledge....so in my case, the shadow is there.....just saying....saved me a ton of money i didn't have....over 30,000 miles on them

 

Excellent advice for MY2002 and previous. Not an issue on the OP's 2005, however. The sentiment applies, however. A once-over of all vacuum lines is a good idea; Although I can't think of one off-hand that would trigger the P0174 and not an accompanying P0171.

 

Hi Jaimster
I didn't realise that the vacuum elbow was sorted out in the later model cars until Aholbro1 kindly left his current post. It was a nuisance to me when I had to change this part which caused rough idle and stalling on my earlier model S Type.

My thoiughts were to save you pulling off the manifold again to do it. At least the vacuum elbow is one problem less for you to think about.

Good luck
Paul

 

the vacuum elbow seems to be in pretty good shape ! i have also opened up another thread on the IMT connector plugs .. i really need to look into those and make sure they are right wiring since i had to splice the wires into new plugs for them..

 

Certainly there are a lot of possibilities that could be causing these codes. Cheapo coils are legitimately one possible cause. Before tossing too much cash away, I would wonder what the fuel trims are. Vacuum leaks that will cripple an engine cannot be seen by eye. Even the dinosaur practice of using starting fluid doesn't cut it anymore. I built a smoker out of a pickle jar and soldering iron that worked terrifically. Found my $16 o-ring leak within minutes that wasn't a MAF or throttle body replacement or some other $$ after $$ endeavor.

 

So I m considering doing a smoke test if this upgrades / repairs don't Do the trick !, possibly buying a smoke test machine online !
also i m charging the battery trying to make sure is fully charge although the battery at over 4 years old . I m debating whether i should just buy a new one ?
i keep hearing an OLD battery can cause all kinds of issues .

 

I ordered a couple of valve stems from Amazon and took out the Schrader valves. Mounted them onto a pickle jar lid with a Harbor Freight soldering iron. Don't pick a jar that the soldering iron touches the glass bottom. I was short on silicone for gluing that in, use plenty because the soldering iron doesn't hold airtight. A bicycle pump, do not use compressed air, on one valve stem, and six foot of tubing on the other. You will want to leave the jar on the ground. Cut the finger tip off a rubber shop glove to tape the tubing in and pull the wrist of the glove over the intake duct where it hooks to your air cleaner. Be sure to tie it in there instead of the throttle body as you will be testing the duct simultaneously. Saturate a piece of cotton sock with baby oil or mineral oil and place it in the jar. Let the soldering iron make the smoke and gently pump it through. Don't make it pressurized, just push the smoke through. It takes a few minutes to get it all the way through but you'll know it when you see it. I doubt you can buy a smoker for $25?

As far as the battery, I agree that the computers in these cars need a solid battery in order to work correctly. I also think that many over-prescribe changing them out. You can have the store load test it but the clerks don't always get it right. I don't know how dependent you are on needing to use the car, but I would charge it overnight to be sure it was full, measure the voltage, then let it sit, periodically measuring for voltage to drop. Understand that a full charge on a battery is directly tied to its temperature. Allow a minor drop if it is colder than when you first finished charging it. It is also important that you have the negative cable disconnected during this evaluation. You are evaluating only the battery via voltage. Having a completed circuit in parallel, in this case the circuitry of the car's "always on" loads, will impart an outside influence to your test.

Check the fuel trims first. They're important. Disconnecting the battery returns the trims to their defaults and it will take running time in order to read them.

Good luck,
Steve

 

hey guys,
so I have replaced the coil packs and I did ran into problems tighten down two of the manifold plenum bols #6,#4 I think so the threated inserts came loose ! did the best I could tihghten those down !!!!!
after putting everything back together : i went to start the car it would just crank NO start till i sprayed cleaner on the MAF sensor so IT started . I drove the car around the block check engine light came on (cylinder 1, 3 misfire and multiple misfire codes )
after erasing codes twice I drove the car back and forth to the gym feels pretty good power no hesitation at all , NO check engine light ON !
a bit rough idling still . I wonder if the MAF sensor is causing issues ???

 

Or maybe a small air leak (quite likely from what you say) - see the many posts about how to check fuel trims.