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Spacer from AliExpress on left (with 90 degree adapter), the other spacer linked above on right (they sent me 3 for some reason). Lots more cat in the AliExpress version. May try both if one don’t work.
O2 sensors are an important element of engine control. They communicate air-fuel ratio measurements inside a car's engine to its ECU to adjust accordingly. They also account for barometric pressure, altitude, and ambient/engine temperature to determine whether the engine burns a lean or rich mixture.
What you are doing is trying to cheat the ECU and even if there are no warnings displayed it does not mean that the engine works at its optimum. Not only exhaust emissions but also engine power, MPG or even engine thermal load may deviate from the norm.
Correct hardware tuning of the engine is not easy and changing of one element affects the correct operation of others. I still argue that $15 or even $50 spacers will not solve the problem and at most it will reassure your conscience that there are no errors on the dash.
O2 sensors are an important element of engine control. They communicate air-fuel ratio measurements inside a car's engine to its ECU to adjust accordingly. They also account for barometric pressure, altitude, and ambient/engine temperature to determine whether the engine burns a lean or rich mixture.
What you are doing is trying to cheat the ECU and even if there are no warnings displayed it does not mean that the engine works at its optimum. Not only exhaust emissions but also engine power, MPG or even engine thermal load may deviate from the norm.
Correct hardware tuning of the engine is not easy and changing of one element affects the correct operation of others. I still argue that $15 or even $50 spacers will not solve the problem and at most it will reassure your conscience that there are no errors on the dash.
These are Rear 02s so they don't have the same impact as the front. Most manufacturers make the only job of the rear 02s is to monitor the cats. Maybe Audi gets more intense with their rear 02s compared to others but most all the time the rear 02s are just there to monitor exhaust flow for cat efficiency.
Yes Tuning is always the correct way but i guess most guys are scared of warranty being voided or the $2000+ tuning cost.
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Yes Tuning is always the correct way but i guess most guys are scared of warranty being voided or the $2000+ tuning cost.
I keep seeing "warranty" mentioned and wanted to remind all of the "Magnuson-Moss Warranty Act" that states that the manufacture can only deny a warranty claim if they can prove a modification was the actual cause of the failure. New car warranties don't suddenly become void if you tune your car.
With that said, being nervous about wildly modifying something we paid a lot for is perfectly reasonable. Oopsie-repairs are more costly for sure.
These are Rear 02s so they don't have the same impact as the front. Most manufacturers make the only job of the rear 02s is to monitor the cats. Maybe Audi gets more intense with their rear 02s compared to others but most all the time the rear 02s are just there to monitor exhaust flow for cat efficiency.
Yes Tuning is always the correct way but i guess most guys are scared of warranty being voided or the $2000+ tuning cost.
You're right, but ... Mounting the second o2 probe behind the catalyst using spacers, i.e. physically removing it from the exhaust stream after removing/changing the cats, sometimes with good results disables CEL, but usually also causes distortions in the control of the fuel mixture composition. The ECU from the second O2 also takes the signal for long time fuel trim and always in the system with the spacers it will impoverish the mixture (even up to a maximum of 30%). This, of course, has consequences in the form of suboptimal engine operation. ECU can handle it, but depending on the algorithm used in the software, usually engine correct operation may be disturbed. From the two bad it is better to disconnect the O2 plugs and drive with CEL. Then the car ECU usually ignores the second O2 probe and controls the mixture based on the O2 upstream of the catalyst. This is certainly the case in the majority of cars.
I keep seeing "warranty" mentioned and wanted to remind all of the "Magnuson-Moss Warranty Act" that states that the manufacture can only deny a warranty claim if they can prove a modification was the actual cause of the failure. New car warranties don't suddenly become void if you tune your car.
With that said, being nervous about wildly modifying something we paid a lot for is perfectly reasonable. Oopsie-repairs are more costly for sure.
Audi put it in writing that my warranty is now void due to the vehicle being tuned. I had to pay for the alternator that went bad. Makes sense to me, the tune puts more stress on the drivetrain.
07-23-2022, 10:23 AM
