Hello all,

I just recently installed a K&N Cold Air Intake and a Throttle Body Spacer on my Chevy Blazer LS. It is a 1999 with a 2006 4.3L Vortec; however, they really don't change that motor so I don't believe that matters.

Anyway, I installed it two days ago and just this morning the check engine light came on as I was driving to work. The engine temperature and oil pressureare normal. I have a feeling it is an oxygen sensor.

Does anyone have any ideas? Would it just be best to hook it up to a diagnostic?

 

maybe the spacer threw the code. If i were you, I would just take it somewhere and have it scanned.

 

There is no use in speculating a reason when there are so many autoparts stores that will read the codes for free. Once you have the code, report back and we'll walk you through the diagnosis further. Just because the PCM may throw say an O2 sensor code, it doesn't automatically mean that particular O2 sensor is bad. Other things can influence particular codes.

And the '06 4.3L doesn't have the same EGR system (if the entire engine was used, intake and all) so your truck may complain about that...

 

Thanks,

I'm going to stop by an auto parts store on my way home and see where the issue is generating from. I'll check back after that.

 

I was on my way to the local auto zone and the light shut off. I continued there anyway and found out that in order for them to runthe diagnostic and get a code, the light has to be on for 24 hours.

Now, when the light came on in the morning, the temperature was about 50 degrees and the air was heavy. When the light went off, it was about 85 degrees. Could that difference make the difference in the mass air flow sensor?

 

They don't know what they are talking about with that 24hr comment. If the light is on, they can read the code. I'm fairly sure that their code reader can only do generic codes so anything manufacturer specific should display the code, but won't have an explaination... And I'm also pretty sure that they cannot read stored codes either.

 

Okay, here's the update:

I stopped by an Advance last night and luckily a friend of mine was working. He ran the code and got P0175. We looked it up in the book which states that it is "Running Rich". How can I go about fixing this?

 

The puter should correct it, and since the light went off, no doubt it did correct it.
Clear the code and see if it comes back on again.

A little more info so you understand what is going on.
The puter uses the O2 sensors to monitor the air/fuel mixture.Your "upgrades" changed the air/fuel mixture and tripped the code. The puter had to make adjustments to bring the air/fuel mixture back to 14.9. Once the O2 sensor readings were back in the normal range, the puter turned the Check engine light off.

On OBDII GM diagnostics the CEL (check engine lights) will turn off after 2-3 normal operations, however the code is stored for roughly 50 normal operations. Operations would be getting the engine and tranny up to normal operating conditions for x amount of time, like 20 minutes, before the engine is shut off.

The light came on initially because you made some "upgrades" and those were more then the puter could compensate for during that operation cycle. It takes the puter a few opertions to relearn and adjust to compensate for the changes.

 

Some K&N filters have had this problem due to to much oil on the filters causing it to throw off sensors. Had a problem with my drop in filter about a year ago.Try cleaning your MAF sensor out.

 

I'll definitely check the MAF sensor. Great idea. The filter was extremely oily when I put it on. I'd also like to check the O2 sensor after the Cat. How hard is it to get out?