bricesaun

I have had cel for over a year now..it started as soon as I changed to full after market exhaust ..I'm getting the 1273 code does anyone know how to fix this

verdict.

1273 implies that the A/F has shift to the lean side of the scale. 1273 = Air/Fuel Ratio Sensor 1 (Bank 1).

Could be an exhaust leak, low fuel pressure or problem with injector(s). Could also be a bad O2 sensor.

bricesaun

Yeah cause I've had quite a few ppl check it out and no one can figure it out and checked for leak..nothing I have even changed the bank 1 sensor 1 and light come back on after about 80 miles

zakmartin

If the O2 bung on the exhaust isn't the right size, your O2 sensor will send a bad reading to the ECM.

bricesaun

Is there anyway to bypass this

MicVelo

Given that it occurred right after exhaust was opened up, the O2 sensor and the ECU are *likely* both doing their jobs correctly. (And particularly if the P1273 code is standalone - that is, not in the presence of any of the other P114x codes for O2 assemblies which would occur simultaneously if it were a faulty O2 related fault) - That's to say that the freer flowing exhaust has caused a change in your A/F Mix - which is NOT in the least bit unusual.

Have you had the car tuned? Not the usual plugs and such; rather, a performance tune such as Uprev/Osiris, Cobb, etc. If not, I'm guessing that's your problem. The A/F has not been corrected for increased exhaust capacity/velocity. Would tend to think that's your best solution....which should be done with any major change in exhaust systems.

Please note that not all changes as such will trigger a code throw. Lots of other factors in the environment, your particular car, fuel quality, etc influence P1273.

If there are no other codes thrown at the same time, e.g., P114x codes for O2 sensors as mentioned, it's not likely that there are other components like the MAF for instance, involved. That's a good thing.

Read your plugs to determine if it's truly too lean and if so, some ECM parameter tweaks are called for. Good luck.

Mic

bricesaun

I have had the car tuned by uprev They did a reflash

MicVelo

Hmmm, OK, strike one.

Try cleaning the MAF? The "read wire" tends to gunk up pretty good and could also cause what you're experiencing. Worth a try at this point.

Even after cleaning and clearing the code, drive a while to see if it comes back.

dboyzalter

iTrader: (3)

What is full aftermarket exhaust?

bricesaun

Yeah I tried maf sensor cleaner that did not work either

bricesaun

Headers cats and exhaust

bricesaun

Headers cats and exhaust

dboyzalter

iTrader: (3)

So you replaced the sensors on the headers? I would imagine getting your old sensors out probably wasnt an option... And I would imagine changing that sensor isnt a pleasure but I would try replacing that sensor on the passenger side header with a new one and then erase the code with your reader and see if it comes back again...

bricesaun

Yeah I did that light came right back on

dboyzalter

iTrader: (3)

Did you do a mail in reflash?

bricesaun

Yeah it was an email then I downloaded it to my ecu

dboyzalter

iTrader: (3)

So you got osiris standard and then got a etune... Or something similar... Did you use an uprev maf sensor? If you have that it could be your problem.

bricesaun

No I never changed the maf sensor still factory

dboyzalter

iTrader: (3)

Its beyond me man... I would call the good people at Z1 they can hopefully get you situated...
https://www.z1motorsports.com/engine...ne-p-9041.html

bricesaun

Yeah Thank you for ur help...but I think I'm just going to have to live with the light just being on.. Its just driving me crazy cause no one can figure out what the problem ....crazy. Lol