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#21
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Request for diagnostic advice to pinpoint least expensive solution to resolve persistent P0421 OBDII DTC
On 18 Nov 2020 13:17:51 -0000, Scott Dorsey wrote:
> What you want to know is in the graphs for the > two O2 sensors and how they track. Hi Scott, Thanks for that gentle reminder, as I will borrow the vehicle today, but I have to check it in their garage, as I only get one chance a day to test warmup conditions (I think, at least, at Silicon Valley temperatures). > But you will not figure the problem out just by looking at the plots, you will > figure the problem out by thinking about how the emission control system works. Well, to tell it to you bluntly, I'm not omnipotent. o I didn't know anything when I first posted this thread I didn't even know the _range_, which I've since learned is basically about ~100 mV for lean conditions, to about ~900mv for rich conditions. Nor did I know when I opened this thread, what the expected differences were for the upstream versus downstream lambda sensors, where the front should be changing far more frequently than the rear (which should read, as much as possible, a stoichiometric ~450mv under steady warmed load). What I didn't know at first was why voltages bounced all over the place. But now I've boned up, a tiny bit, on the fact that the bouncing around of the voltages is "normal", at least for the upstream side, since the engine computer is constantly adjusting the ratio (within seconds) depending on a whole bunch of factors, not the least of which is engine loading. Further honing what I didn't realize at first is that there are two states: 1. Steady state (which is where most of my prior measurements lay), & 2. Warmup state (which is where I need to focus, as you had advised me). What I need is what most sites don't provide, which is I need to learn more about this warmup process of the cat, since it's a 'warmup efficiency' DTC. I only get about a minute (or two at most), right? >>When do I take the readings once the engine is warmed up? > > All the time. You take them before it warms up, you take them after it warms > up, you take them over the course of driving around. What you are looking for > is trends and correlation more than specific values. Yes. But. I belatedly realized I need to focus specifically on 'warmup efficiency'. o My main focus now revolves around how to diagnose 'warmup efficiency'. Obviously I need to figure out what 'warmup' even means, which I need to do as my homework, since I'm not even sure how long warmup of the cat lasts (the sensors only take ~20 seconds to warm up, but I'm not sure how long it takes the cat to warm up, nor, if a cat can even warm up twice in the same day given Silicon Valley typical warm nightly & daily temperature ranges). I'm gonna borrow the vehicle today but it's wet outside so I'm not sure if I'm gonna crawl underneath to check the rear lambda sensor; but I will at least check the live OBD data during the first 20 seconds of the lambda sensor warmup and then the first few minutes, where I'm guessing a cat warms up in, oh, I don't know, within the first five minutes perhaps? o I'll look at an engine temperature reading (coolant perhaps?) o Then I'll look at the front & rear sensors (and what they do over time) I may need to buy an infrared thermometer to check how the cat warms up in the first five minutes with the vehicle on jack stands; but no sense in doing that until I learn more about how the cat _should_ warm up, as the numbers won't mean anything if they're measured under the wrong sequence. >>I don't have the necessary equipment to save or see graphs. >>o I can only see the live data as it happens. > > Well, that's useless. So you're going to have to plot it on semilog paper > by hand. Your scanner does not provide ANY plotting functions? My OBD scanner _does_ provide plotting functions; but it's second hand (I picked it up at a garage sale for a few bucks). It works fine for live data, but I don't have the cabling or software to view the graphs. o Harbor Freight item #60693 Cen-Tech OBDII/EOBD Deluxe Scanner It also does 'freeze frame' but I haven't even started to look at what that means to me, in terms of how I can use that to diagnose warmup efficiency. In summary, I started out with the wrong assumptions, and I ran the wrong tests, and I didn't know how the system worked... but I'm reducing my ignorance by reading up on how the system works, and I'm gonna focus on the all-important warmup process, where I think I only get one chance a day. -- Experience is knowing which measurements to take, when, where, & why. |
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#22
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Request for diagnostic advice to pinpoint least expensive solution to resolve persistent P0421 OBDII DTC
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#23
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Request for diagnostic advice to pinpoint least expensive solution to resolve persistent P0421 OBDII DTC
On Wed, 18 Nov 2020 18:41:17 -0000 (UTC), Arlen Holder wrote:
> o P/N MN195802 Lancer 2.0L, 2004, Exhaust Manifold Repair Kit > (includes manifold with catalytic converter, gasket, and nuts) Drat. The recall was already performed; but they didn't replace the warmup cat. o All the dealer did was reflash the PCM (i.e., P0421 didn't come up then). Just in case, this appears to be the $400 + $40 tax recall parts: o P/N MN195802 Lancer 2.0L, 2004, Exhaust Manifold Repair Kit <https://www.mitsubishipartscentral.com/p-exhaust-manifold-catalytic-convertor-lancer-2004-mn195802> "Original equipment genuine Mitsubishi part exhaust manifold / catalytic convertor Fits only 2004 Lancer with 2.0l engine This kit includes the gaskets and hardware for installation. California certified." I'm not sure yet if there are two cats, but it appears the car may have o A warmup cat, plus, o A regular cat Since this recall talks only about the "warmup cat" melting due to a poorly coded PCM (which they reflashed, apparently, as per EMR-05-001REVII TSB). -- So Mitsubishi knew about this P0421 warmup-cat problem all along. |
#24
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Request for diagnostic advice to pinpoint least expensivesolution to resolve persistent P0421 OBDII DTC
On 11/18/2020 1:41 PM, Arlen Holder wrote:
> On Tue, 17 Nov 2020 23:35:03 -0500, wrote: > >> Oh Arlen > > Permanent plonk! (the fact such creepy disgusting people exist is scary) > Oh I love it when you plonk me, plonk me again and again you beast of a man |
#26
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Request for diagnostic advice to pinpoint least expensivesolution to resolve persistent P0421 OBDII DTC
On 11/18/2020 4:10 PM, Arlen Holder wrote:
> On Wed, 18 Nov 2020 18:41:17 -0000 (UTC), Arlen Holder wrote: > >> Permanent plonk! (the fact such creepy disgusting people exist is scary) > > BTW, for those who wish to block this prolific worthless piece of **** > troll, below you will find plenty of his socks & some of his threads. > > By blocking those socks, your Usenet experience immediately gets better. > Youse my hero arlen, you no all about internet |
#27
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Request for diagnostic advice to pinpoint least expensive solution to resolve persistent P0421 OBDII DTC
Update:
o <https://i.postimg.cc/QdDv3H7V/obd33.jpg> *a.h.r is 99.9% garbage spam* Aghast, I happened to use the dejagoogle feature to look at the a.h.r newsgroup, which, much to my chagrin, is more than 99.9% worthless spam. o <http://tinyurl.com/alt-home-repair> o <https://groups.google.com/g/alt.home.repair> Given the lack of value in a.h.r, I will no longer be posting the results of this thread to that newsgroup, preferring to put the updates on r.a.t which, thankfully, isn't almost 100% worthless spam as a.h.r clearly is. I'll also drop ca.driving, such that this is the only worthwhile ng: o Request for diagnostic advice to pinpoint least expensive solution to resolve persistent P0421 OBDII DTC <https://groups.google.com/g/rec.autos.tech/c/u3mtjAGgwK8> BTW, the vehicle passed smog today; but that doesn't solve the problem of diagnostics since it only made it through the intermittent window. -- We never fail to solve our DIY repairs, working together, for all. |
#28
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Request for diagnostic advice to pinpoint least expensivesolution to resolve persistent P0421 OBDII DTC
On 11/18/2020 5:30 PM, Arlen Holder wrote:
> Update: > o <https://i.postimg.cc/QdDv3H7V/obd33.jpg> *a.h.r is 99.9% garbage spam* > > Aghast, I happened to use the dejagoogle feature to look at the a.h.r > newsgroup, which, much to my chagrin, is more than 99.9% worthless spam. > o <http://tinyurl.com/alt-home-repair> > o <https://groups.google.com/g/alt.home.repair> > > Given the lack of value in a.h.r, I will no longer be posting the results > of this thread to that newsgroup, preferring to put the updates on r.a.t > which, thankfully, isn't almost 100% worthless spam as a.h.r clearly is. > Weeze gonna miss you ya no it all arrogant prick. You may have been trolled but not spammed but yoose to dum to no the difrince yu is. |
#29
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Request for diagnostic advice to pinpoint least expensive solution to resolve persistent P0421 OBDII DTC
On Tue, 17 Nov 2020 23:06:39 -0000 (UTC), Arlen Holder posted for all of us to digest... > > The goal is to learn how to diagnose a P0421 using an OBDII scanner. > > Request for diagnostic advice to pinpoint least expensive solution > to resolve persistent P0421 OBDII DTC given... > > 1. College kid's early 2000s Mitsubishi fails OBD-only smog > 2. Neighbor asks me to help out (as if I know anything, which I don't) > 3. However, I can borrow the vehicle & run live tests via OBDII scanner > > Question is, what do I look for in terms of "live data" to help diagnose? > > DETAILS FOLLOW: > o 180K miles, circa 2003 or 2004 model year (I think) > o Service Engine Soon has been reported to be on for a year > o New pre cat 02 sensor had reportedly already been installed 3 months ago > o Lambda O2 Sensor always tests OK on the OBDII scanner > o CAT always tests OK on the OBDII scanner > o All other registers always test OK on the OBDII scanner > o The P0421 DTC is set "sometimes" when the CAT register is set > o I cleared the DTCs a few times but the P0421 came back each time > o I/M Readiness lasts only about a day or three before DTC occurs again > o Always the same DTC and always only that single DTC > o Warm Up Catalyst Efficiency Below Threshold Bank 1 > > The question isn't "Does it require a new cat", nor is the question > "What parts can we blindly throw at it until it finally works". > > The question is what "live data" do we look for to _diagnose_ > what the problem actually is (and what's the options for repair). > > My main dilemma that I'm asking for your help on is what > do I look for in the "live data" when I take it for a test > drive with the OBD scanner? > > BTW, I'm familiar with the concept of the Federal Test Procedure > (also known as the Drive Cycle), but I don't have the specific > drive cycle for this specific vehicle (but I can guess based on > the drive cycle for other vehicles, although not the same marquee). > > PHOTOS FOLLOW: > o <https://i.postimg.cc/KzTmdCBx/obd01.jpg> Failed smog > o <https://i.postimg.cc/nrYpL73W/obd02.jpg> 180,000 miles > o <https://i.postimg.cc/65tBmj3x/obd03.jpg> 1 DTC with all registers set > o <https://i.postimg.cc/fRbDwVmH/obd04.jpg> P0421 below threshold, bank 1 > o <https://i.postimg.cc/437G9j8V/obd05.jpg> Lambda sensor OK > o <https://i.postimg.cc/kgh9D7y7/obd06.jpg> CAT OK > o <https://i.postimg.cc/901KSB8c/obd08.jpg> EVAP, MIS, FUEL, OK > o <https://i.postimg.cc/26nfHhN5/obd07.jpg> Live data page 1 > o <https://i.postimg.cc/v8vJcQQC/obd09.jpg> Live data page 2 > o <https://i.postimg.cc/vHqCt3xz/obd10.jpg> Live data page 3 > o <https://i.postimg.cc/NjKSJm1w/obd11.jpg> Live data page 4 > o <https://i.postimg.cc/T3BSZ195/obd12.jpg> What values do I look for? > > QUESTION: > o What do I look for in terms of "live data" to help diagnose? Here you go. As always check electrical connections. <https://www.autocodes.com/p0421_mitsubishi.html> By the way your scanner is not giving you live data that you can can use. You need something more advanced. You don't need the "cheapest" fix-you need the "correct" fix and shooting the parts cannon at it doesn't work. -- Tekkie |
#30
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Request for diagnostic advice to pinpoint least expensive solution to resolve persistent P0421 OBDII DTC
On Wed, 18 Nov 2020 21:10:04 -0000 (UTC), Arlen Holder posted for all of us to digest... > > On Wed, 18 Nov 2020 18:41:17 -0000 (UTC), Arlen Holder wrote: > > > Permanent plonk! (the fact such creepy disgusting people exist is scary) > > BTW, for those who wish to block this prolific worthless piece of **** > troll, below you will find plenty of his socks & some of his threads. > > By blocking those socks, your Usenet experience immediately gets better. > > An example of how this same troll trolls his own threads is he > o What the lying MSM wonąt say about our election > <https://groups.google.com/g/alt.home.repair/c/gev1rluwTtA> > > And he > o Democrats commit greatest theft in US history > <https://groups.google.com/g/alt.home.repair/c/D1byNJ9r_N0> > > These are all the same troll's sock (IMHO): > o From: " > > o From: "Colonel Edmund J. Burke" <lbone@go usarmy.com> > o From: "Gimme that ol time ACF." > > o From: "Tekkie©" > > o From: Anonymous > > o From: > o From: > o From: Bucky Breeder > > o From: chrisv > > o From: Cleanup in Isle 3 > > o From: Dan > > o From: Ed Pawlowski > > o From: gray_wolf > > o From: Greg Carr > > o From: Grumpy Old White Guy > > o From: > o From: Jeff Hickling <"1st > > o From: Jenny Telia > > o From: Jim Joyce > > o From: Jim S > > o From: Jimmy Kauffenhak > > o From: > o From: Joe Beijing > > o From: Joe Bidet > > o From: Joel > > o From: Jonesy > > o From: Mark > > o From: Monty > > o From: nilsson > > o From: Pabst Blue Ribbon > > o From: Ralph Fox > > o From: Ralph Mowery > > o From: Raven > > o From: Robert Marshall > > o From: Scott Lurndal > > o From: Shadow > > o From: The Horny Goat > > o From: The Sidhe > > o From: vallor > > o From: Voltarin > > o From: Yrrah > > o From: "STD.COM ish jew kike paedophile BARRY Z. SHEIN 700 Washington St B'righton Mass" > > o From: Bill > > o From: Bucky Breeder > > o From: Char Jackson > > o From: Charlie+ > > o From: Gary Dingle > > o From: gray_wolf > > o From: Jim H > > o From: Knut Sveinssen <kss@arbitrage.> > o From: Mark Lloyd > > o From: Well Arlen I have never posted this kind of trash. You first blocked me because I criticized your nymshifting. I have even posted valuable information in a reply to this subject. I have posted other information on other topics you have asked about. I suggest before trashing me you contact me at my email. It is real as some other posters can attest to. I am a reasonable person. If you have a problem with me let's discuss it. You are only hurting yourself. Could someone not on his killfile list please pass on this. -- Tekkie |
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