yes, I completely agree that the bureaucratic snarl could use a complete review and makeover. There needs to be a better process to allow people to get their cars in compliance.

But I think it needs to be pointed out that these regulations didn’t come from nowhere and nothing. It needs to said once and a while that California would be unlivable without these regulations.

Unlivable.

That what it was for my two aunts in the mid 1950’s. They both died during the worst of the smog inversions that made the air deadly, and for so many other people as well.

Today SoCal has many times, ( 50x ?) more cars now vs the 1940’s and 1950’s , but despite that the exhaust and the air is so much cleaner. Breathing it may not 100% healthy. But unlike my aunts, you will wake up alive.

Z

Yes, the last few 40-50 mile test drives were done like that. The last one, at night, as I was approaching a stop light there was a car behind me. I stopped for the light and the car pulled into the left-turn lane to my left. Annnnndd... it was a local cop. :eek: :icon_doh: I guess he had fulfilled his quota, or something, because he didn't stop me. I went to AAA the next day and got the permit. It's stamped and everything, but I'm supposed to write in the date I use it. So... I'm keeping it in the car, with a pen, and if I'm stopped I guess I'll quickly jot down the date. :D

Make sure the ink is quick drying 😁

80 mile round trip today, mostly freeway. CAT monitor still shows INC. Frustrating.

The other day, before the trip posted above, I took a short drive and noticed that I had pending rich codes again. When I got home I removed the original Jag MAF and replaced it with the new DENSO version. After another drive the pending codes went away. I'm on my 2nd tank of gas and no more codes. Yaay.

Now the bad news is that the CAT monitor will not set. Last night I drove an almost 200 mile round trip, at speeds from around 70mph to 80mph. The fuel trim numbers looked OK. But when I arrived I checked and the CAT monitor was still not set.

I dug around and found a document posted by @Don B with all of the $06 TIDs. So, I connected the scanner today and drove around a bit and looked at that data. The first issue is that the document tells me what the codes mean, but I have no idea what the values are supposed to be. My cheapie and old scan tool generally shows the test ID, the MOD, a MIN and MAX, a MEAS and a STS. I assume the MIN and MAX are the lower and upper ranges of whatever value may be in the MEAS value. STS I suppose means STATUS.

ALL of the O2 sensor related tests show STS of OK. Can I assume that means the test passed?

The ONLY tests that show a rather significant different are tests $1C Upstream HO2S 11 minimum sensor current for test cycle mA and $1D Upstream HO2S 21 minimum sensor current for test cycle mA.

$1C shows MIN of ---- MAX of 8EFE MEAS of 747A and STS OK
$1D shows MIN of ---- MAX of 8EFE MEAS of 6C46 and STS OK

Does anybody know if this is significant? Does the fact that every test shows OK mean that there's nothing wrong with the O2 sensors?

O frabjous day! Callooh! Callay!

I found a fleaBay seller selling new (but no box) Denso upstream O2 sensors for about $125 each. I bought two. They came sealed in bubble wrap and did look new and genuine. I'd been dragging my feet because everybody's been selling these things for close to $300 each. I had removed my upstream sensors in my driveway a week, or so, ago. I installed the new sensors on Sunday and went for about a 10 mile drive to Foster's Freeze, and about 10 miles back. STFT bounced around more than before, although generally small numbers positive and negative. LTFT were generally negative all the time. ranging from -1 to -10, with -5 and -7 being the most common. The downstream sensor voltage still bounced around, but seemed generally a bit higher, a bit more consistently, than before. Lots more 0.4 and 0.5 and 0.8. I came home, waited a bit, and went on another 6 or 7 mile trip. Still no joy on the cat monitor.

Today, on the second cold start after replacing the sensors, I drove to the shop, about 5 or 6 miles. When I had a break this afternoon I put the scanner on it and lo and behold the highly coveted P1111 code came up!! I made a beeline for the smog shop and had it smogged. I can now drive the beast for the next couple of years,

Yaay!!

That is fantastic news! Your persistence paid off!

Cheers,

Don

Early in August a friend came down for some Dodgers games. I drove him around in the Jag. And... the second night, when approaching his hotel. the CEL came on and it went into Restricted Performance. Again. Arrrrrrgh! :mad::mad:

I unhooked the air filter lid and made a small gap between the lid and housing and drove that way for a couple of days and the CEL went out. I buttoned up the filter box, connected the scanner and, sure enough, the fuel trims looked too rich. I ordered up a Mahle air filter to replace the cheapie Amazon one I had installed for testing purposes and drove around for a couple days. STFT is now about 0 to +0.8, LTFT in small negative numbers at idle. At mid-throttle, up to maybe 50mph, the STFT runs between +9.0 and +15.0 and the LTFT runs almost identical numbers but negative. At high speed it's similar but the numbers are all in the single digits. This does look somewhat better than the cheapie filter.

I've driven around for about a week, lots of stop and go and short freeway jaunts, and no CEL. I have never had a car, in the 51 years I've been driving, that was so freaking sensitive to air filters.

The cheap ass parts these days are much worse than the cheap parts we old timers used in past decades.

technology has discovered how manufacture parts that look OK but are actually worse than flimsy.

I also bought some very cheap Amazon air filters about 2 years ago. They came in a 4 or 5 pack, I don’t recall which. The smell was odd when I opened the vacuum wrapped package . Like stale food, spoiled milk almost. Their were white flakes
coming off of the filter if you tapped it hard on your hand. No way was I going to use them

i was just embarrassed they I’d bought them, as I had already been burned by cheap parts on eBay earlier. Slow learner..,


I called Amazon, but the time frame for returns had lapsed already by the time I opened the box, so I was SOL there. I think I was out under $20 for them.

Z

they’re not sensitive to air filters…what’s metered by maf is what it works with. you have an intermittent problem

Fair enough, and I'd love to know where to look. I've tried three MAFs, the original Jag that came with the car. A genuine DENSO (which is on the car now) and a cheapie Amazon one I was using for testing earlier in the year.

Maybe an off-the-wall question. That oval shaped tube that goes through the inner fender panel from the filter box... which way should it point? Can it be reversed or blocked it it's out of position? I removed that access panel and felt around and mine is pointing rearward. I don't think it's ever been fiddled with by me. That's the only possibly intermittent thing I can think of. Although that would be a sort of air filter issue, and not a metering thing.

Agree with xalty here. No way that this is caused by the airfilter element. When it suddenly works after you have touch the air filter lid, I would suspect the wiring or connector to the MAF sensor

Except the codes are too rich on both banks - i.e. too much fuel/not enough air, so clearly the air filter is always going to be a suspect (in fact it's the very first thing the DTC Summaries list says to check for those codes).

As to why a partially blocked or knock off air filter could cause the MAF to read incorrectly, you have to look at how the MAF works. It doesn't measure the air flow through the air intake, it measures a tiny sample of that air flow and extrapolates the total air flow from that sample. You can see how a partially blocked, or non standard air filter could cause the MAF to misread the total. Whether that is the case here is a totally different question, but either way it makes sense to fit a new OEM air filter to eliminate that possibility.

Re the oval shaped intake tube, here is how it is fitted on my car (ignore the red highlight):-

https://solnerja.com/wp-content/uplo...208_173310.jpg

It's been a minute since I posted an update.

I have fiddled and futzed to no avail. I stopped to think and deduced that the last remaining common denominator was the fuel pressure regulator, which I replaced with a Delphi unit like 2 years ago. So, just for kicks, I enlisted the help of ChatGPT.

When I first got this thing, after replacing the fuel pump and switching the car on I got a huge fuel leak from the regulator. Apparently all of the o-rings were hard and dry. Instead of sourcing new o-rings I replaced the regulator which, in retrospect, may have been a mistake. I suspect the regulator may have been marginal, but was masked by all of the vacuum leaks in the engine. As the vacuum leaks were repaired the rich running problem got worse.

Anyway, after putting in my symptoms and my testing up to that point, AI sez it's likely the FPR. The current one idled about 38psi, jumped to around 42 with vacuum unplugged, but only dropped to around 32 when I applied like 25 inches of vacuum to the regulator. I sourced a new Delphi unit and the idle pressure dropped to 36. No vacuum produces around 42-ish, and 25 inches of external vacuum produces 28-ish. AI liked these numbers a lot more and the fuel trims went from substantially negative to single-digit negative. After driving tests, the car would eventually start throwing super-high-negative trims and go into restricted performance.

I had been using the original Jag MAF so I put back my DENSO MAF that I'd purchased several months ago. The short term trims immediately showed single-digit to low double-digit positive numbers. Things looked far more normal than before, after a few test drives the CEL turned off, and AI was pleased. But one gremlin remains.

From time to time, often when coming to a stop and then proceeding slowly with very tiny throttle usage, like in a parking lot, the thing will spike up to -25 short term and stay there until I hit the throttle hard a few times. Then ST trims drop to normal. This doesn't happen every time, it's at random. Sometimes just sitting at a stop light it will go from say +3 to -15 to -25 for no apparent reason.

One thing I have noticed is that the TPS % at idle, with foot off the accelerator will jump around. I see numbers like 2.0% to 1.0% to 0.8% to 1.2% to 3%. It will pick one and stabilize for a bit, then do it again. AI says this is a problem.

OK. My question for the hive is - is this normal for these Jag TPS sensors? Should they remain steady, with just tiny fluctuations?

Also, any other suggestions?

BTW, I replaced the injectors with a rebuilt set months ago and the problem didn't go away. I put the old injectors back, same problem. So, I put the new ones back in again. I don't think there's a bad/sticky injector because both banks throw trim numbers within a couple of percent of each other.

Your disc rotor looks odd ? Irregular dark and light patches….

May just be the lighting.

Z

That's not my car. @dibbit was kind enough to post this in response to another question I had regarding the air filter intake nozzle.