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2005 Nissan Altima 2.5L P1273 Fault: O2 Sensor Replacement Causes Code, TID $43 Value Exceeds Max

Model: 2005 Nissan Altima Fault Code: P1273 Posted: 2016-03-03 18:34

Hello, I recently replaced the pre-cat and oxygen (O2) sensors on my 2005 Nissan Altima 2.5L, but after the replacement, the vehicle started triggering fault code P1273. I cleared the codes and performed an ECU relearn procedure. The initial scan via OBD Fusion shows a Mode 06 issue where one parameter exceeds its maximum value: TID $43. TID $43 is labeled as 'Manufacturer Defined' with a current value of 32,990 (max allowed: 32,932). I'm trying to understand what this specific TID represents — is it related to an O2 sensor? If so, is it the upstream or downstream sensor? I initially replaced both the upstream and downstream O2 sensors due to a prior P0420 code. The upstream sensor was upgraded to NGK/NTK (which I understand is equivalent to Nissan OEM), while the downstream sensor was an inexpensive $20 unit from Amazon (APW AP4-325). The MAF sensor has been cleaned, but the check engine light remains on. Below are some key freeze frame data points: - Fuel System 1 Status: 2 - Fuel System 2 Status: 0 - Calculated Load Value: 31.76% - Engine Coolant Temperature: 188.6°F - Short-Term Fuel % Trim - Bank 1: 0% - Long-Term Fuel % Trim - Bank 1: 9.38% - Engine RPM: 2400 rpm - Vehicle Speed: 57.17 mph - Absolute Throttle Position: 7.84% The fuel trim values indicate a lean condition, but the long-term trim at 9.38% is not extreme — could this still be within acceptable range? I'm wondering if the issue stems from the aftermarket downstream O2 sensor or another underlying factor such as vacuum leaks or fuel pressure issues.

Related fault codes
P1273
Comments (5)
Anonymous 2016-03-04 08:23

Only fault code present is P1273. This typically indicates an upstream air-fuel (AF) sensor detecting a lean condition. Ensure you used a genuine Nissan AF sensor — aftermarket units can cause misreads or false codes. Check fuel pressure; low pressure may lead to lean readings. Also inspect for intake air leaks, starting with MAF cleaning and checking for vacuum leaks downstream of the MAF. Why were sensors replaced initially? That might provide key insight into the root cause.

Anonymous 2016-03-04 10:31

I replaced both O2 sensors and the exhaust manifold (with an aftermarket one from eBay) due to a previous P0420 code. The upstream sensor is now NGK/NTK, which matches Nissan OEM specifications. The downstream sensor was a low-cost $20 unit from Amazon (APW AP4-325), which I later learned may not be compatible with the 2005 Altima's ECU.

Anonymous 2016-03-07 15:01

The new O2 sensor has not arrived yet. After cleaning the MAF, the check engine light returned. The freeze frame data shows a lean condition, but long-term fuel trim at 9.38% is relatively stable. Fuel system status remains consistent (Bank 1: 2; Bank 2: 0). Engine temperature and RPM are within normal range. I'm still investigating whether this points to sensor inaccuracy or another issue.

Anonymous 2016-03-07 16:28

No immediate red flags stand out — the fuel trim is adjusting for a lean condition, though 9.38% long-term trim isn't alarming. Still, it's worth checking fuel pressure levels. A classic diagnostic tip: perform the 'carburetor spray test' to detect vacuum leaks after the MAF. Also, confirm there are no exhaust leaks or other unreported codes — these could be contributing factors.

Anonymous 2016-03-17 17:09

Turns out the issue was caused by the low-quality downstream O2 sensor. After replacing it with a genuine NTK OEM sensor, the P1273 code has disappeared and the vehicle is running normally. Thanks for all the helpful suggestions — this experience highlights the importance of using factory-recommended sensors in older Nissan models.