Exhaust lambda value too high

RAU03MACH

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its reading basically like potentiometer reading in current or voltage
sending signals
and you would need a star 2 tester for that
i go by fuel psi
 
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GTamas

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How do they run the test anyway?

Tested at idle? Tested at 3000RPM? Under load on rollers? Or just holding RPM in nuetral?

Is the reading reflective of a result obtained exactly at that particular set of conditions?
They put a sensor into the tailpipe, ca. 40 cm deep. Then measure it at idle and ca. 2500rpm. Without load.
 
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GTamas

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I checked codes... Everywhere just 111, system pass.
But I noticed that the vacuum hose on the top of this part (is it a valve?) was kinda not fully attached. It was barely connected. I know it is on the line connected to the AIR pump, but don't know yet its function. Could this be related? Maybe it was not shutting down the air feed in closed loop?
20240531_214133.jpg
 
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GTamas

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I checked codes... Everywhere just 111, system pass.
But I noticed that the vacuum hose on the top of this part (is it a valve?) was kinda not fully attached. It was barely connected. I know it is on the line connected to the AIR pump, but don't know yet its function. Could this be related? Maybe it was not shutting down the air feed in closed loop?
Well this did not solve it unfortunately. Next I will change the spark plugs and inspect the O2 sensors. I will also ask someone to do a vacuum leak test with a proper smoke machine.
 
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GTamas

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New spark plugs did not help.
Driving a full tank on highway with premium gas and cleaner additive did not help.
Gonna replace O2 sensors next.

Also ordered an obd1 scanner to check codes. Check Engine Light flasher revealed no codes.
 
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have you tried checking maff and cold air intake sensor on the air box tube
Not yet. How can I check the cold air intake sensor? Which one is that?
The Maf I can check according the Haynes manual.
 
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have you tried checking maff and cold air intake sensor on the air box tube
I found IAT Intake Air Temperature sensor in the manual, this is which you mean? Then I know how to check. I will have a look at it, thanks for the tip!
 

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They make a cleaner for them, CRC brand if I remember correctly. Just sprays on and dries really quickly. The MAF is in the air intake tube. DO NOT use anything other than MAF cleaner on it.
 
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They make a cleaner for them, CRC brand if I remember correctly. Just sprays on and dries really quickly. The MAF is in the air intake tube. DO NOT use anything other than MAF cleaner on it.
O2 sensors replaced. Lambda values did not change much, they are still around 1,6 way too lean. What do you make of the old sensors, how do they look? They are the factory installed originals.
20240620_154719.jpg
 
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So what I plan to do now:
- read codes when the innova scanner arrives
- replace the EGR valve
- smoke test for vacuum leaks with proper smoke machine (not just me puffing smoke)
- inspect/clean MAF and IAT sensors
- recheck the exhaust again for leaks
- check AIR system operation
 
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By the way, there are two small holes on the stock mufflers, for the condensation water to exit. There's some exhaust gas coming out of it when the tailpipes are blocked by hand. I guess this is normal. Or what do you think?
 

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