These are my NO readings over the years at 15mph -allowed max is 760:
2010 (twice) 2012 2014 2016
656/752 742 740 875
No.
You are referring to diagnostic monitors on OBDII vehicles that are relied on for emissions testing. These monitors are cleared/erased when the battery is disconnected or the PCMs faults are erased or overall memory is cleared.
Your car has a tail pipe emissions failure, not a computer “readiness” failure.
Thanks @Nevada_545
THis article talks about ECU being cleared:
http://www.smogtips.com/six_things.cfm
"its internal self-test monitors are erased. Without these required Emission Monitors your vehicle can not pass the smog test. You will be required to drive between 100-200 miles and over the course of a week"
I am confused?
An '87 is an OBDI system. No monitors that can be read with a scanner like OBDII.
That smogtips article applies to OBDII.
@cwatkin - I tried your method on freeway on D3
But i could not get up to 500rpm below redline
I got just over 4k rpm - just over 70mph - Redline is at 7k
Any tips?
The engine does not have enough power to get above 70 mph.
Try a lower gear.
Driving 95 MPH in third gear is not going to clean pistons and valves in any amount that will make a difference, this is not how vehicles are repaired.
You should have the vehicle checked by a repair shop that is licensed to repair vehicles that fail the emissions test.
@"Bill Russell"
Engine will go beyond 75mph on D3 but it was unsafe
Should I try D2?
@Nevada_545
I will be going to a m/c
why was it unsafe?
Our engines used to get carboned up in the 40s and50s too. The effect was pinging at normal timing settings. The cure was slowly pouring water down the carb of a warmed up engine running about 3000 rpm from a pinched paper cup. That was on cast iron heads on cast iron blocks. Not sure what effect it would have on a modern car. It would be interesting to try it on a car headed to the junkyard.
My car’s NO reading is almost at the max level even for 25mph - a m/c gave me a price of $275 to fix it. He did not tell me what he is going to do. Does the (faulty) Cat causes high NO?
And you did not ask him what he was going to do? Why?
He won’t say it - he wanted my business - that was my understanding. Maybe I could ask him again when I make the appointment - he also does not speak English well
Wouldn’t suspect number one in this case be the O2 sensors and NOT carbon on the pistons?
Unless you have serious blow by and low compression…I honestly cannot think of any reason why you would have excess carbon on the top of the pistons. AND…you can actually look down a spark plug hole and see the piston top…and or send a long screwdriver down to meet and sample this carbon if it exists.
Like I mentioned before…and as @cwatkin stated…Water injection would make the piston crowns SHINE… I used to do this stuff back in the days of carburetors just to play around. But it not only works…but works extremely well. It has to be metered properly… When I was 17 I used a Pickle Jar and Spring Water from my local farm. I used a brass aquarium valve that I think was meant to regulate or slow AIR…but it worked like a charm… Clear tubing also is needed so you can see the “flow rate”…nice n slow… A few Pickle Jars worth of water and those pistons were shiny as could be… Silly I know…but I was more than a little silly back then… It was fun and educational.
Back to the real issue however? I would be considering 2 new O2 sensors if this were my vehicle. If you can change a light bulb you can replace your O2 sensors…in fact if they have never been done…your way overdue…they do not last forever.
You could also use that additive that guarantees you will pass emissions tests… look it up. Ive never used it meself but…they make it…though it may not be avail in CA…but its on the “net” for sure…
Blackbird
Most probable cause on my non-EGR car is the CAT, which gives high NO (also in the link I posted earlier). O2 sensor is also probable.
I am also experiencing a different exhaust smell - the cat is original - it is prob dying. I am scheduling a diagnosis and repair - just working out the details.
I did take it on freeway at 6k rpm (1k below the readline) on D2. It still runs the same way - engine etc are reasonably clean, I suppose
Does it smell like Sulphur ?
I don’t know how Sulphur smell - what does Sulphur smell means? What are u getting at?
I think he means sulfur dioxide, commonly known as “rotten-eggs-smell”.
Sulfur alone has no smell.
nevermind…