99 S70 Base - P0172, P0171 and P0174

[E Showell]

Ran about 150 miles in a day recently with no codes and no other issues relating to the throttle body. I am getting the feeling I need some suspension work, however. Putting this in the "solved by replacement of ETM with XeModex rebuilt unit" category.

[precopster]

I thought that the codes appeared AFTER replacing throttle.

During the malfunction of the throttle mixtures are usually rich because the flap isn't allowing as much air to the cylinders. This can result in a coating of carbon on the O2 sensor. Long term ETM failure and continued driving can damage the cat converter.

Resetting baselines with the battery disconnect and touching terminals gets a new perpective for fuel trims. Another fix may have been a light cleaning of the O2 sensor and a good long drive to take in new feedback from the cleaned sensor.

[E Showell]

The ETM was clearly shot. It needed replacement. After replacement and a battery reset, the only code that appeared was an evaporator leak from a loose gas cap. No other codes since the battery reset.

[precopster]

The ETM was clearly shot. It needed replacement. After replacement and a battery reset, the only code that appeared was an evaporator leak from a loose gas cap. No other codes since the battery reset.

I'm not doubting that your previous ETM was shot. You would have had codes galore pointing to ETM in any case.

What I was pointing toward is that the battery reset got rid of the P0172 code and that a failing ETM can have consequences for other components even AFTER replacement.