2000 Isuzu Rodeo V6 DOHC 3.2L, OBD II Codes

I have been having trouble with my 2000 Rodeo. The check engine light has come on and it is running rough and hard to start. I went down the Checker Auto Parts and hooked up the OBD II ScanTool, and it gave me P0171, P0172, P0174, & P0175. Those are all System Too Lean Bank 1 & 2, and System Too Rich Bank 1 & 2. So when I clear those codes, they will stay off for about a day or two, then come back on. One time I got a P0300, which is a random cylinder misfire. I replaced the MAF sensor, when I first got it, because it gave me that code. Then I took it to our local Midas Auto Service, and they told me that it was the Accelerator Pedal Position Sensor. I replaced that, they were wrong, still got codes. I've cleaned injectors, I've put in a new Fuel Pressure Regulator, I just don't know what else it can be. I was thinking maybe Throttle Position Sensor or maybe the O2 Sensors, maybe even a couple new Catalytic Coverters. I just want to know that when I get in my car to drive it somewhere that I don't have to have a tow truck on speed dial. Thanks

First stop going to MIDAS for diagnostics! An accelerator postion sensor will never genrate any of those codes ever! There retarded if they think it will! Your rebranded GM needs to have the fuel pressure checked as well as any vaccum leaks checked!

I had the fuel pressure checked and the mechanic told me to get a new fuel pressure regulator, so I did...........I guess I need to have it checked again, but if I put a new part in there would it need to be checked again?

sure if it wasn't the correct repair or it was faulty or installed incorrectly!

check maf sensor????? mass air flow senser?

I put in a new MAF sensor when I got it. Also I got the fuel pressure regulator from the dealer.

So you need a proper diagnosis done then!

Probably wouldn't hurt. It's also using about a quart of oil every 1000 or so miles. I've read that happens a lot with Isuzu, but I was just wondering since my car isn't running right that maybe it's running too rich and the gas is washing out the cylinders? But while it's sitting there idling you can here the intermittent misfire through the exhaust. Could it be the EGR valve? What would I use to clean the MAF sensor? It's only getting about 12 miles to the gallon also, specs say it should be getting about 16 around town, and 22 on the highway. Thanks for all the help

MAF cleaner from CRC or brake and parts cleaner but be gentle! what is the fuel pressure at right now? does it bleed off?

I'm not exactly sure what the fuel pressure is right now, but I'm pretty sure that it is bleeding off. When I let the car sit overnight, it will fire up right away when I start it. But when I have been driving it for a little bit, and then let it sit for about 20 minutes, it won't want to start. It will turn over and over, and if I don't give it a little gas then it won't start. Sometimes it'll start but will run at about 200 rpm, not 2000, for a few seconds and then it's like the fuel finally reaches the engine and then it idles higher. Also, it idles rough right after I start it, after I'd already been driving it of course, so I don't even know where to start. It's not giving me any other codes but the System Too LEAN/RICH Bank 1 & 2.

okay but I'd think if it was bleeding off then it wouldn't start right up after being parked overnight. in fact I'd think the opposite. If it was bleeding off I'd suspect longer crank times, rich exhaust on start up etc! A hot start problem is a little differentt! I'd check the egr or at least clean it out if you don't know how to check it and you need a fuel pressure gauge to verify what the fuel pressure is and what it's doing! As well it be nice at cold start after sitting all night to see what the coolant sensor and the ambient air temp are reading and how they change as it comes up to temperature! Has anyone ever cleanned the throttle body on this truck? And the IAC

I haven't cleaned anything except the injectors since I've had this car, and I've only had it for a little over a year. I'm not quite sure where the EGR valve is on it. I think that it is on top of the intake manifold towards the back of the engine. It looks like it has solenoid on top of it. There is a little piston in it, correct? The check engine light will go off sometimes if I drive it while it's cold, but it still has the codes. How would I go about cleaning that stuff? Where do I hook up the fuel pressure gauge? I just want this car to stop using oil, get better gas mileage, and be the car that I wanted it to be when I bought it. Thanks Again!!!

sounds like a cracked intake gasket to me. O would put a vacume guage on it.

As I stated in my 2nd post but someone's not listening or not finding anything! If you want it to be like new and stop using oil you're probably going to need professional help! At the very least you need a manual that tells you where the egr is, how it works, where to hook the fuel pressure gauge up etc, etc! Actaully pro help is probably the best investtment! And not MIDAS or any muffler shop monkeys for that matter! A shop that will likely cost more and specialize in diagnostics!

I took it to a local shop here in Montana, and they hooked it up to their diagnostic machine. Turns out that the fuel injector on cylinder # 4 was toast. Also put new Isuzu spark plugs in. Thanks