: PO171 and PO174 to lean

01-24-06, 06:45 PM
i have an 00 catera sport and it is keeps spitting out these codes. so far i have replaced the O2 sensors on bank1&2 position 1. the light went out for a week and it came back on. could it be the MAF or the other 2 O2 Sensors. if it was in my buget i would change them all. Please can somebody help. I also have another question my tank level light is on and will not go out I know that there is a float in the tank and a float switch is there a way to chack them. Also are they seperate parts (tank,float,switch) or all in one.
Please Help Me.

01-24-06, 08:24 PM
In the first place, you shouldn't have replaced the O2 sensors because they are just saying that you have a "too lean mixture" which means to me that it's doing it's job. You may be right in saying that the MAF is faulty or it could be another factor. Try and see if there are other codes aside from what you are getting. I don't have the book to interpret the code exactly but someone here may have the complete info on the codes you are getting. Do you have any other symptoms or problems aside from the code?

01-24-06, 08:40 PM
No that is the only two codes that are coming up. I have an OBD2 tool and it only reads those codes.

01-24-06, 10:54 PM
Now, I am not a mechanic but after working on my Catera ever since i got it trying to fix every bit of problem myself whenever i can, I would say that it seems to me like a MAF sensor fault. I had mine replaced because it was giving false reading causing the fuel and air mixture to mess up. But before i replaced mine, I had the classic symptoms of MAF sensor fault like the stalling after a while of driving the car and having to cool it down first before you can actually drive it again.

01-25-06, 06:18 PM
Mine does not stall when it gets hot or after driving but it comes very close to it. The RPM's drop really low and then it jumps up to around 800 to 900 then goes back to normal. I changed the fuel filter and ran two treatments of fuel injector cleaner though it and the light stays on but got more power. go figure. now here is something to think about. it was raining one day and i went out to go home after work started the car and the light went out, two days later it came back on.

01-25-06, 08:55 PM
It seems to me that your MAF is really going bad. There was a thread here about the price of our MAF. Do a search because for some reason, I got a more expensive one from my favorite store GM Brasington. It turned out that the guy who bought it cheap made a call to one of the dealers and for some reason, was given a sensor with a different part number which turned out to be cheaper than the one i got. Do a search on this forum and you might be able to buy the sensor cheaper. It's easy to install so i suggest that you do it yourself and save some bucks.

01-25-06, 08:59 PM
But before getting a new MAF sensor, try cleaning that valve that controls the idling air. It's located on the driver side of the top of the engine. It's easily visible. You need some torx screw driver to remove them and i suggest that you don't dis-assemble them as described in one of the threads here because it's not easy. Just try cleaning it by dipping it in some kind of solution that may dissolve the grime inside. If you are confident enough, you can try disassembling the thing to give it a thorough cleaning. Again, do a search here on some instructions on how to do it. If you can't find it here, try going to the Yahoo site and it may be there that i saw it once.

01-25-06, 10:38 PM
It's either got a vacuum leak or it's got a faulty MAF.

01-26-06, 12:31 PM
I thought it mite be a vaccum leak because I had the oil cooling system repaired about 7 months ago and it started about a couple of weeks ago. The dealer i had fix it never worked on a Catera before and it never had the problem when I took it in. I will let you guys know hopefully tomorrow because it is in the shop for another coolant leak. Oddly enuff they did not notice the check engine light. The same dealer that fixed it before but this time they brought a cadillac mechanic over to fix it, so they say? Thank you guys for your help hopfully I will have good news.

02-14-06, 12:13 PM
Sorry it took so long to get back to you guy's. Had to replace the MAF to get the light out. Got it from www.rockauto.com for $114 plus shipping best deal I could get. Hope this helps somebody out.

02-20-06, 07:58 AM
My wife just took her '01 Sport in for an oil change. The next day, the check engine light comes on, with P0171 code (scanned at AutoZone). After some searching, I'm now aware of the potential causes (vacuum leak, MAF sensor, etc.), which we'll look into. I'm wondering - how likely is it that the guys doing the oil change caused this? Is there any way to prove that? I'm hesitant to take it back to them out of fear that they'll cause more trouble or rip us off somehow. Also, any clue as to how much these repairs should cost? (i.e. replacing a tube or the MAF sensor) Thanks in advance...

02-20-06, 12:38 PM
It is unlikely that they did caused a problem. As for changing the MAF sensor it is easy and you can do it yourself. As for a vacuum leak I do not know the cost of that. I have read that sometimes you can run feul injector cleaner through the engine and it will fix it. If you are going to take the car in and have it checked take it to a chevy dealer the labor cost is cheaper and they can do minor things like that. If they tell you what is wrong some dealers will let you buy the parts and they will in stall them. Hope I could help.

02-21-06, 10:44 PM
Thanks for the input, caberts1. Must have just been a coincidence in timing. We went back to the same shop and were told we needed a new fuel filter, and the MAF sensor needed cleaning. This seems to have done the trick. My next move is to get my hands on a service manual so we can start taking care of little things like this on our own, especially now that the warranty is up. At least the car will be fully paid off in a few more months.