1996 TOYOTA AVALON HIGH HYDROCARBONS ONLY

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#1
TO anyone that may be able to shed some light on my darkened adventure. I have a 1996 Toyota Avalon that has had a new California cat new oem oxygen sensors, new oem air filter, new synthetic motor oil, new oil filter, new egr modulator new oem spark plugs, transmission service, the egr system, valve plenum and vacuums have all been removed and cleaned to a like new condition, new pcv valve car has been hooked up to Toyota service department tech diagnostics and they say ratio on lamda is perfect 14/7/1 fuel trims are perfect compression is 180 on all cylinders no vacuum leaks no codes pending or otherwise. the car will just barely not pass California smog due to high hydrocarbons only and just on the 15/50 test passes on the 25/25 what could this possibly be i am at a loss and have dedicated so much time and money and effort into this car it is a great car but damn it man what gives? thanks to anyone with extensive knowledge in this field i don't know where else to turn!!! jvstrength
 

nickb2

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#2
Ok, I will give this a shot. Try cleaning Mass air flow sensor/meter. Check timing. Swap positive crankcase ventilation (PCV valve) with OEM if the new one was a universal jobber part. PCV valve is only a few dollars. Brake cleaner can be used to clean MAF sensor element and to check timing, check out the attachment. Also check for any minor leaks in exhaust. A smoke tester is great for this.

A 1996 is not so sophisticated in regards to emission testing. You could have a slight exhaust leak around the cat as those gaskets suck large on these toyota's. Up here in quebec canada, we don't have emission testing, nada, zilch and it's quite funny to see the jalopies running around that just won't die. Dash is lit up like a christmas tree and still puttering around.

Oh, and try a different brand of gas. I know that calif gas standards for sulfer are regulated. I don't know, but at this point, after reading the barrage of stuff you threw at this car. Like shooting with a blindfold on. Hit or miss.
 

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billr

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#3
You say "Calif cat", but is this Calif. emissions testing? If so, what part of Calif? What caught my eye is the "15/50 test" and the "25/25", I live in the SF Bay area, subject to the most stringent emissions testing (I think), and for both my '95 and '97 vehicles the testing is only for 15/25 mph. If you have a typo in what you posted, please correct. Bogus info only leads us to give you bogus advice!
 
J

JVSRENGTH

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#4
TO billr yes california cat a walker brand and iam out of Bakersfield in southern california and the 15/25 test that i refer to is 15 mph at 50 percent load and 25 mph at 25 percent load and yes you are correct that is all they test for are the two different speeds i was also referring to the load at that speeds.
 

billr

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#5
Okay, I never knew what the dyno loads were, just that they were related to vehicle weight. Is this a manual trans or auto? Either way, what were the engine rpms at the 15 and 25 speeds? I hate to divert folks from batauto, but this may be a case where you have to search on a Toyota-specific forum.

Short version of the story: I have some '95 Saturns and ran into problems passing emissions recently. After much hassle, I found that the "by the book" test is to use 2nd gear (manual trans) for both 15 and 25 mph. However, there is a loophole in the CA regulation that allows the test operator to use either 1st or 3rd, "if necessary". The Saturns do a lot better using 2nd/3rd for 15/25, so I needed to find a shop that understands that and would run at those speeds; as they legally could but are not obligated to do. Point is, maybe the same situation exists for your car. Discrimination is alive and well in this part of CA life, so don't annoy the shop you are working with!
 
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to nickb2 thank you for the downloadable info after reviewing the possible causes chart there is something that strikes me as a possible in the brake booster line as the breaks after doing a brake replacement are mushy they do not grab but they do not stop real well at all and the pedal travel is distant i believe there may be an issue with that the pcv valve is new and all parts on vehicle have been fitted with toyota oem parts i know better than to get aftermarket on a toyota and toyota is actually quite stringent on there emmissions testing you mean to tell me there are more stringent and complicated systems than toyota. the timing is not adjustable on this car is it not or is there a way to manually adjust it without computer control. would a gas cap that has the ventillation pressure valve in it but being a generic cap have anything to do with high hydrocarbons getting through and wouldnt a code be stored if rhe maf was reading incorrectly or abnormally. i will check these things and clean the maf as you said and get back to you thanks for your time and the exhaust system has been completely sealed no leaks to speak of. the tech from toyota said that the cat is working at only 50 percent based on the hydrocarbons going in and the hydro coming out they were 500 something and coming out were at like 283 was his determination is there another way to test the cat to see if it is bad or only partially working. do you suppose that the cat may not be getting hot enough as the vehicle runs very steady and efficiently so it never really gets above normal operating range, thanks again for your insight i will be in touch
 
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#7
I have never seen a scanner report amda is perfect 14/7/1 fuel trims are
using a lambda reference has me asking WHY WHY WHY

first everything is STOCK and the parts are TOYOTA especially the O2 sensors?
OEM is a brand and we refer to OEM as genuine TOYOTA only - just confirming


With scanner I would look at - ECT, and FT,s - they say perfect but?
That ECT is a critical input-
Are you using OIL? maybe look at plugs - wet, dry, black, tan? Remove oil fill with engine running - excess blow by? Maybe for test do NOT let PCV breath crank fumes...
 
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that is a good point the gearing it is an auto transmission however the 25 test passes it is only the 15 that does not and it is just a matter of 3 to 5 to 9 parts per million over the allowance so it is something extremely minute but very frustrating it has been tested 4 times now and each time it is the 15 test and each time it was over just a couple parts per million than the last. if the cat was working at 50 percent as a tech had said from toyota wouldnt that reading be much higher. i think they were b.s.'n me. back to the point i wonder what gear they are running with but they do have to run at a certain rpm within the speed range correct? also would a different tire size change the reading either larger than stock or smaller seeings how the 25 passes what if a smaller tire were put on to enable the motor to run harder or faster rather to obtain speed and tach range or would it not make that much difference? thank you for your interest in my dilemma i hope we can figure it out this one is a doosey!
 
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scanner didnt report the lamda reading the input numbers to the lamda calculator came up with those numbers and that is what toyota showed me however like i had said previously i believe they hosed me from the very beginning the spark plugs are dry and have no apparent fouling or abnormality of any kind present they are new but the old ones coming out while worn were all even in wear with no problems distinctive with oil cap off the activity inside is busy oil squirts all over the place within the valve covers there is a leak though from the valve cover gasket in the front not a whole lot but enough to put fresh oil on the manifold and motor that is not enough to drip on the ground but a noticable spread on motor. with the cap off there is air that sputs out rythmicly. i will run tests as you suggested tonight and see what i come up with to the point of desperation trying to get this well running car passed the emmissions and have to much invested to turn back now plus it has sentimental value to my girlfriend it was her Dads and he was original owner and he is recently decended. Thanks for your consideration I will get back to you soon with progress report.
 

billr

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#12
"but they do have to run at a certain rpm within the speed range correct?"

No! That's my whole point. They have to keep vehicle within range (a rather wide one), but the engine rpm isn't specified. It is suggested that 2nd be used normally for a manual trans, both 15 and 25, but they are allowed to use another gear. I don't know for sure, but expect that testing of auto-trans cars is similarly subjective. I'll see if I can find the link to the Calif ARB site that spells that out.
 
J

JVSRENGTH

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#13
I do not have a scanner that reads live data however i know of a shop by my house that will let me hook up to his dyno for 90 bucks and run tests. I have not done that yet but that is the only access to such resources that I have. I would spend a couple grand for one if you know of a quality scanner that allows input for testing parameters and functions.I researched to buysuch a tool some years ago and found so many options and could not decide on what to buy due to so many different products. I was leaning toward at that time a 5 gas exhaust fume detector that reads the output of the emissions from the tail pipe to diagnose faulting systems however I also wanted a tool to run input and read with graphs and such and to be compatible with multiple makes. however that is off the subject at hand so as to not bird walk too far I will run what tests were suggested here on this forum that i can preform without the dyno and test the other suggestions this weekend at the repair shop with the dyno.i need to make a list of all that i should test and the directions of doing so. I really appreciate all the feedback to my inquiry. I am anxious to discover what the cause of thisis so I can share it with everyone. Something to give back to all who have put in. Thanks again everyone, I will be in touch, in the mean time any other suggestions is more than welcomed or any questions as well i have numbers and papers of smog results and anything else anyone would care to look at. thanks so much again. James V.
 

billr

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#14
Since you have OBD2 on that '96, there are many low-cost (< $30) ways to get live-data. Do a search on "ELM327" or "ELM OBD2".
 

nickb2

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#15
A obd2 dongle via wi-fi or bluetooth seems to be the trend. However, it is not the adapter so much as the software. http://www.scantool.net/software/

Some have dyno applications and such. Do your research, try to see what software will meet your needs and see if compatible with a cheap elm327. They go as low as 15$ on ebay, however, I did my own research, and I am still researching on this site, what will be good for me. I see alot of programs that can be used with the elm interface. I just have not worked with them yet. I am used to high end dealer scanners and geneysis/snap etc.

I do like the graphing that you can get on a pc/laptop as I work alot with graphing to see underlying trouble that does not always pop a code. The screen is bigger and put multiple monitors/graphs and drive with the laptop on passenger seat.

Check this outhttp://scantool.imechatronics.com/downloads.htm It is a link to compatible elmscan software. Some are free, other cost but most likely have better options and bigger database. :thx