I have a 2004 S type Jaguar 3.0 V6. For a months I have had a check engine light on. The only code is P0430 Bank 2 (driver side) I have replaced both pre/post 02 sensors left side. When installing 02 sensors, battery was disconnected/reconnected. Engine light reappeared days later. I have reduced gas mileage. Engine running chronically rich with some gas fumes after turning car off. No idle or other performance issues. What else should I eliminate before replacing direct fit cat on driver side that could be damaged...could it be a MAF sensor? Mass Air Flow? I have replaced correct spark plugs 20k miles ago. Air filter is fine. No apparent vacuum leaks. Need advise Thanks

 

Could be the cat, could be coils or plugs or even a vacuum leak.

I'd put my money on a failed/failing coil

 

Look at OBD live data. Warmed up, parked. Is it running CL (closed loop) on both banks at idle and if you hold revs about 2500 for 30 secs? What are LTFTs (see my sig), both banks, both times?

Can't really be MAF as both sides would be bad - but see what LTFT show.

 

OUCH!

On a more serious note - have you looked at the coils to ensure they are working correctly?

 

I appreciate your advise
What are the proper steps to check/test coils?

Thanks

Scott

 

You can use a cop Tester or swap all coils to other side see if problem changes banks. More often than not when you remove the coils they will be contaminated with oil or water or both, replace any that are.

 

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Is there also a test for resistance high and low for coil check? as well as the visual check? Where would I get those specs at/
Thanks

 

PCM already tests - see codes PDF/JTIS.

If you want to test ohms (can't see much point) pull a good one and compare.

 

if you haven't already, download and install jtis, it covers up to and including 2004 s type.

it includes full instructions on diagnosing and testing the ignition system.

 

I am not one to say dismiss the problem but this might be a modification you can live with if it comes down to replacing the cats. Read this and see what you think.

Link P0430 Cat treshold Bank 2 code, Need some help. - Jaguar Forums - Jaguar Enthusiasts Forum

Brutal has a good reputation on this forum and I respect his opinion.

 

Still waiting for trims - post #3

There's good useful data easily obtained so why guess. Do that if the data doesn't appear to help.

 

+1 to jagv8, you could save yourself a load of time and money.

 

had that code P0430 came up on reader as inefficient cat ,dealer replaced cat as it was still under warranty (s-type 2006 V8)

 

I finally got the Trim: LTFT and STFT tested
I need advise on what could be causing stype to run rich, lower gas mileage (16.7 in city)
and again persistant Bank 2 cat. inefficiency P0430 code:
============
Pulled sparks, correctly gapped and not fouled (installed oem sparks 25k ago)
plugs 1,2 left side had light oil (indicating need to replace valve cover gaskets??)
Air filter clean..no vacuum leaks or sounds.. idle steady just under 1.5 rpms and good...

Pulled coils, 1 slight oil, wiped. Tested prong connector tabs in coil, with type meter, all coils, same #'s for all so thinking coils okay?*Did not do/use COP tester for coils.*
reinstalled.
*I did just replace left bank pre/post oem O2 sensors...

==============
Tested LTFT:
At Idle: 12.5 = steady
2500 rpms for a minute: = 0
===============
Tested STFT:
At Idle: = oscillated faster from 3.9-7.8 ( Avrg.5.8 )
2500 rpms for a minute: = oscillated slower from .7-3.9 ( Avrg. 2.3 )
===============

With the rule of 10%:
12.5% LTFT would exceed = mean?? at idle computer adding too much fuel?
Other rule of 10% being gap between averages: 12.5 - 5.8 = 6.7 ( within limits??)

Is possible malfunction MAP sensor result of PCM incorrect injector communication because of MAP?
or am I thinking too deep here??
===============
Where to go from here?
Install right bank 1 pre/post new O2 sensors or not necessary? Install new MAP sensor, or not necessary?
Injectors involved? Should I replace Coils Left bank 2 cylinder 1-3 as a precaution... or just get aftermarket oem match direct fit bank 2 cat?
===============
Cleared code... return in a day...

Any advise??

Thank you so much

Scott
Arizona

 

You should have LTFTs for each bank so 4 figures.

What are you meaning about O2 sensors? I can't understand you

An LTFT 12.5 does not mean it's running rich. It means it's running lean and so is adding fuel to try to correct the extra air (which is what is seen).

Too soon to guess cause without both bank figures.

 

I just got this error two days after replacing the air filter with a K&N type. Could doing this affect this error or is this just coincidence?

 

I'm not a big believer in coincidence.

I'd check LTFT values. Maybe first put in an OE filter.

 

In my case I received the P0430 on my 2002 S-type 3.0 because my coils were going bad.


I experienced very poor acceleration and difficulty going faster than 40mph - knew it was coils going bad but needed the car daily and kept driving it. I also had some very short periods where during acceleration the MIL light would flash - which told me the catalyst converter was getting damaged - didn't have a choice but to keep driving.


I changed all the coils and reset the MIL - car worked like new with no MIL for quite a few months before the P0430 showed up. I used some concoction in the fuel tank that kept the P0430 off for enough of a period to get thru emissions testing. The light came back and stayed on, drove car for over 18 months - replaced the O2 sensors which didn't make a difference and then the cat itself. That resolved the MIL.

 

I do remember there have been a few times I tried accelerating hard too soon after start and I would get misfire errors. I cleared them as I have cleared this one and the error hasn't come back, however, I haven't experienced any power loss.

I do see my MPG has dropped to around 25 from 28. This sucks considering my daily drive is about 90 miles.

I very rarely add gas additives. Perhaps that is what I need to do.....

 

You shouldn't get those misfires. There's something wrong and an additive is not likely to fix it.

Lower MPG also points to a fault. It may be running rich, will damage the cats.

Fuel trims may reveal some of what's going on.