So, a couple months back I sold my 05 GX to pick up a 95 LC, and after a few month honeymoon I really missed the GX. So after swallowing up my pride and figuring out my angle with my wife, I convinced her it was better for the both of us for me to get a different GX. Score.
I searched a bit and found myself a keeper. 07, 140K, southern truck, non-nav, blah, blah, blah... The only issues were small -- a rain sensor not adhered, and a few codes registering in the computer. The guy I bought it from said he pulled the codes and they were CAT related. He said the dealer wanted $800 or something to fix. I thought, nope, not for me, but let's go ahead and use that as a negotiation tactic and discount the truck assuming responsibility for the fix myself. I drove it, and it drove well. I also suspected this guy wouldn't Google if his life depended on it, so I thought, "heck, it might just be a fuel cap..." So, I pulled the trigger and voila, a new truck!
The standard 4 lights are illuminated... CEL, VSC, TRAC and skid. I pulled the codes and got p1442, p1445, p0420, p0430. So, the SAIS is not working as it should. It's not making any weird noises, but we've got a stuck valve. We've also got some readings around the CAT that say fuel isn't being burned off as it should. So I took some pics to remember the codesm and used the OBDII reader to clear the codes. Codes gone.
After driving 15 or so miles, the lights came back as I suspected they would. This time I got 4 readings of p0420 and p0430, which tells me all 4 O2 sensors are either not functioning, or there's still a emissions/fuel mix issue the sensors are seeing. Interesting enough, the SAIS didn't pop up again...
So that leaves me to where I am. I figured the SAIS thing is probably something I should deal with now anyway, so I ordered the Hewitt bypass. I also figured the MAF could use a good cleaning to help read right for fuel draw BEFORE the upstream O2 sensor was getting a read in the event it's pushing too much fuel. My hypothesis is that the MAF could be so dirty that the system is simply dumping fuel at a higher rate than needed. I've also smelled some gas stink, which would corroborate that thought.
My question to you folks is this: would you approach the situation any different, or am I on the right track? Could a dirty MAF cause excess fuel input and cause the downstream O2 sensors to read bad levels and toss 430 and 420? OR, do you think the sensors are bad? Should I be treating the SAIS, or would you leave it? Is there a downside to tricking the system into not running?
Would love your thoughts. I definitely NOT an expert. But I try to play one on TV.
I searched a bit and found myself a keeper. 07, 140K, southern truck, non-nav, blah, blah, blah... The only issues were small -- a rain sensor not adhered, and a few codes registering in the computer. The guy I bought it from said he pulled the codes and they were CAT related. He said the dealer wanted $800 or something to fix. I thought, nope, not for me, but let's go ahead and use that as a negotiation tactic and discount the truck assuming responsibility for the fix myself. I drove it, and it drove well. I also suspected this guy wouldn't Google if his life depended on it, so I thought, "heck, it might just be a fuel cap..." So, I pulled the trigger and voila, a new truck!
The standard 4 lights are illuminated... CEL, VSC, TRAC and skid. I pulled the codes and got p1442, p1445, p0420, p0430. So, the SAIS is not working as it should. It's not making any weird noises, but we've got a stuck valve. We've also got some readings around the CAT that say fuel isn't being burned off as it should. So I took some pics to remember the codesm and used the OBDII reader to clear the codes. Codes gone.
After driving 15 or so miles, the lights came back as I suspected they would. This time I got 4 readings of p0420 and p0430, which tells me all 4 O2 sensors are either not functioning, or there's still a emissions/fuel mix issue the sensors are seeing. Interesting enough, the SAIS didn't pop up again...
So that leaves me to where I am. I figured the SAIS thing is probably something I should deal with now anyway, so I ordered the Hewitt bypass. I also figured the MAF could use a good cleaning to help read right for fuel draw BEFORE the upstream O2 sensor was getting a read in the event it's pushing too much fuel. My hypothesis is that the MAF could be so dirty that the system is simply dumping fuel at a higher rate than needed. I've also smelled some gas stink, which would corroborate that thought.
My question to you folks is this: would you approach the situation any different, or am I on the right track? Could a dirty MAF cause excess fuel input and cause the downstream O2 sensors to read bad levels and toss 430 and 420? OR, do you think the sensors are bad? Should I be treating the SAIS, or would you leave it? Is there a downside to tricking the system into not running?
Would love your thoughts. I definitely NOT an expert. But I try to play one on TV.