NOX ville
07-31-2013, 12:13 AM
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Join Date: Nov 2006
Location: Houston, TX
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NOX ville
Hello, having some problems passing CA smog.
Already replaced the O2 sensor and the temp sensor.
The top numbers are before i replaced the O2 sensor and the lower ones after I replaced it.
Upper image is before the O2 sensor and temp sensor replacement. I really expected to see more of an improvement. AS you can see we are still running lean WITH a new O2 sensor, so I am thinking that the sensor wasn't the issue, Although everybody agrees replacing it was a really good idea and the next logical step. In consulting with the friendly smog tech, he is of the opinion that the cat is the last thing to be dealt with and with the current numbers I need to do something to richen the mixture. There is plenty of room for more fuel with HC so very low.
SO.... Plan of attack is...
1) I am going to check the settings on the FPS. I have no idea where it is presently, but haven't touched it, ever. Perhaps a PO or tech set it wrong many years ago. God help me I am also going to carefully pull and inspect the DME to check for bad traces and clean the large connector contacts.
Wherever the switch is set now, I was thinking 1 or 2 ticks to richen.
2) I will back probe the O2 sensor to check for voltage and/or adjust the air bypass on the MAF. This brings up rebuilding the MAF, or at least inspecting it. I may have to do that, but don't want to mess with too many components at one time. I think checking the temp sensor within the MAF might be a good idea and possibly cracking the box just to have a peek.
ANY helpful advice is greatly appreciated as I really can't afford a cat right now and this whole business is really starting to get me down. Supposedly, these things can pass emissions without a cat and the smog tech said that getting the mixture correct to begin with is the way to go.
ALternatively, I have a few odd thoughts like checking the fuel pressure or cleaning the injectors in case they have clogged up through the years. The important thing to consider is that testing costs time and money and I am running out of both.
Already replaced the O2 sensor and the temp sensor.
The top numbers are before i replaced the O2 sensor and the lower ones after I replaced it.
Upper image is before the O2 sensor and temp sensor replacement. I really expected to see more of an improvement. AS you can see we are still running lean WITH a new O2 sensor, so I am thinking that the sensor wasn't the issue, Although everybody agrees replacing it was a really good idea and the next logical step. In consulting with the friendly smog tech, he is of the opinion that the cat is the last thing to be dealt with and with the current numbers I need to do something to richen the mixture. There is plenty of room for more fuel with HC so very low.
SO.... Plan of attack is...
1) I am going to check the settings on the FPS. I have no idea where it is presently, but haven't touched it, ever. Perhaps a PO or tech set it wrong many years ago. God help me I am also going to carefully pull and inspect the DME to check for bad traces and clean the large connector contacts.
Wherever the switch is set now, I was thinking 1 or 2 ticks to richen.
2) I will back probe the O2 sensor to check for voltage and/or adjust the air bypass on the MAF. This brings up rebuilding the MAF, or at least inspecting it. I may have to do that, but don't want to mess with too many components at one time. I think checking the temp sensor within the MAF might be a good idea and possibly cracking the box just to have a peek.
ANY helpful advice is greatly appreciated as I really can't afford a cat right now and this whole business is really starting to get me down. Supposedly, these things can pass emissions without a cat and the smog tech said that getting the mixture correct to begin with is the way to go.
ALternatively, I have a few odd thoughts like checking the fuel pressure or cleaning the injectors in case they have clogged up through the years. The important thing to consider is that testing costs time and money and I am running out of both.
