Did you stop and then have to restate engine after "splutter etc.?
yes when I stopped at the gas station
You replaced Fuel Pump or had replaced by a shop?
I did in 2015 (dense fuel pump) not oem
Have you replace the gas cap yet?
No, I couldn't find it yet but I am in search for it
Do or did you let your engine idle for long periods (5, 10, 20 or more minutes)?
it happened while I was driving around 80mph. spluttered and it slowed down, I then cruised 65mph till next gas station
Are battery cables (not just on post, but into wire harness bracket) free of white powders build up (resistance issue)?
yes they are free of powder buildup.
You may also be getting bad gas. I would think in your area gas good but IDK. Any chance of this?
Very possible as it happened once before, 2 years ago, when I had half tank then fuel gage dropped to E then back to half.
Are you checking coolant level by looking in radiator after 8 hour cool down?.
I did that last week yes and its very red and cleaned, but I lose some from the refill jug about 2 ounces
If you had to restart: Sounds like fuel starvation. If so, very likely you have a store DTC indication a lean condition. Did you check with tech stream?
No but no check engine lighted popped up
Also where is pictures of CAT temps form tech stream at the various RPMs?
is there a cat temp in Techstream? I did measured temperature with infrared thermo after driving couple hours on the highway but not sure if I did it right. Passenger Side Cat was measured around 400F(- +).Driver Side Cat was measured 360F. again I need to do it right.
Where is the pictures of intake to head area you said you'd get and post?
Next post
If fuel pump replaced 3 years ago with OEM, it should not be bad. It is possible you just had a bad one installed 3 yrs ago. It's also possible you a resistance problem.
Not OEM. I replaced it with Denso, very possible is not even original Denso as well (corrupted parts market here) but I check the OEM is around 150$ and the one I got is around 65$
BTW: The seal on top of fuel tank, should also be replace at same time as fuel pump.
I don't remember replacing it
I know it's a lot of question. But this issue is one many have been try to solve. It's a difficult one to do in the shop, and 10 times more difficult over the internet. Data and detail is only way you can even have a chance at getting this diagnosed. I've no doubt an new CAT will stop the P0430. But issue causing must be found first. The fuel pump may have been it. But you need to get a good compression test now. I suspect you've been loading up the CAT(s). Than your long HWY drives are clearing them somewhat. You may be good to go now. Only time will tell.
@Julian Stead made a good point. Many drive around with low compression and don't know it. Low compression does not mean bad oil rings or oil lose.
A good compression test is so important here. You need to learn how to do yourself. Then either you do, or teach your shop mechanic how too. I know you feel compression is fine and it may vary well be. But 110-120PSI done within 40 minutes of hot shut down is not Okay.
I will try to find a better mechanic for the compression test when I get a chance
Condition of the spark plugs and coils are questionable also.
plugs have 50K on them and they are okay( didn't do the gap) and coils are in good condition with new boots on all of them.
The why of a CAT going bad with weak fuel pump, is something I'm looking into now!
My thinking is somewhat along same lines as you. I'm really stabbing in the dark. But to summarize below:
Weak fuel pump is causing a rich condition by way of EUC correcting for lean. That this leads to clogged CATs.
Here's my thinking: The ECM confused, and corrected for lean condition of weak fuel pump. The amount of air intake (oxygen), would be as designed, This assumes no vacuum leaks and good air filter. ECM would add fuel, by way of setting long term fuel trims for a base-line of increased fuel (LTFT positive %). As ECM worked to reach the goal of 14.7:1 stoichiometric (air fuel mixture).
Running cooler/"rich" can give a CAT code, as can running cold due to bad thermostat. It can also clog the CATs. Rich condition foul spark plugs and cylinder heads build up carbon & gunk. The EUC works to correcting for rich condition now, due to poor spark.
Prolonged idling would make clogging of CATs, happen even sooner.
I've one I'm working on now:
History showed: both P0420 & P0430 along with AI secondary switches BK 1 & Bk 2 stuck closed.
I found fuel pump was fault for lean condition and engine stall. This may have been accentuated over time; by battery cables & connecting harness having built up acid oxidation (increasing resistance to entire electrical system). Further history shows fuel cap was replaced. So someone at least "thought" it bad. It's replacement had no effect in stopping stall/lean condition, as was present afterwards.
I saw no signs of heat damage. Like excessive ceramic dust or broken up ceramic materiel between the forward and aft CATs or damage to ceramic honey comb like falling apart or discolored at rear of meterial.
The CAT bk1 did showed sign of clogging (post #18), but only at upstream on face. Back side of first CAT materiel was clean, so was secondary CAT. Note: With the VVT we've two CAT ceramic honeycombs separated, in each side with O2 between them. They also have and A/F (not O2) sensor upstream.
I replaced bk 1 CAT, and stop the P0420 from returning, so far. But kept seeing bk 2 CAT (P0430) coming back over time. I had tried many things in attempt to clear CAT in BK 1 on (P0420). Like 44k, Cataclean, seafoam fogger even sprayed seafoan directly into CAT through A/F port and did many high RPM (5K RPM for 5 to 10 minutes) HWY drives to burn out valves, cylinder heads and CATs of carbon and gunk.
I ran a camera into A/F port (b1s1), to see how upstream face of CAT looked (first 3 pictures in post #18). I though perhaps all my efforts to clean CATs, had cleared gunk from fuel system, intake and cylinders. Dumping it all on CAT faster than it could burn off, thus re clogging the relatively new CAT on BK 2. Turns out that was not the case. CAT bk2 looked clean when scoped. It was just very poorly
installed. So it's safe to assume, the gunk on face of CAT bk1 was there before I first saw the vehicle or added any cleaners. So I can assume CAT BK 2 was a clogged condition also, prior to it's replacement. I found other signs CATs clogged. One such, is both secondary AI switches stuck closed.
With the USA introduction of the 100 series VVT in May 2005 production. They introduced the VVT heads and AI system. Additionally they made many other variation. Some refinements for performance some for environmental reasons.
The AI secondary switches, ride on-top of rear water by-pass joint. The primary switch rides in valley just in front of starter, which this one gets the hottest (I've no issues pending or active with it). I've seen both primary and secondary switch from severely overheated engine. That blew the engine warping the heads, melted intake manifold and plastic of VVT cam and knock sensors. Those switch appear okay (I'll test one day). These secondary switch have air tubes that blows air into exhaust. By way of a tube that runs to an addition smaller exhaust port, just above each main exhaust port on heads. They (secondary switches) run open for about 90 seconds with a blower fan blowing air (oxygen) into exhaust, during cold start, to heat CAT up faster. To see both go bad with two clogged CATs, indicates a relationship.
That relation is likely when open the first 90 second, back pressure from exhaust due to clogged CAT, exceed AI blower fan pressure. So the exhaust may flow into switch, gummy them up. I'll be pulling one secondary switch when I get a chance. I expect to find gunk & carbon in it.
