I have a 94 S-10 PU with the W code V-6. It is giving a code 45 which reads, Rich exhaust indication - oxygen ( O2) sensor voltage stays high after one minute of engine run. (left sensor on the dual sensor engines). Questions; Will a new sensor potentially cure this problem? Is the sensor a symptom of a different problem? Where are the sensors located? Any help would be appreciated. I am working out of town and do not trust driving it in the current condition. Thanks, Patrick
Pat,the oxygen sensor is at fault-it is reading slow and is not doing the rich-lean-rich that a normal functioning sensor does. The computer watches the time that it takes to do this,and if it doesn't, it throws a code(and in your case,code 45). The sensors are mounted on the Y-pipe and there are two of them. Depending on how many miles you have on your truck,you might have to heat the sensor up with a torch to remove the sensor easily. Change the sensor and then remove your memory fuse to clear the code.
Carl, Thank you, I appreciate the help. I took a good look at your car in Salem...very nice and the color looked great. Patrick
In a nutshell Code 45 is caused by a few different things Fuel pressure too high- air fuel ratio will be too rich ECM seeing higher than actual RPM- ECM will increase injector pulse width (on time) to match increased RPM signal. Fuel canister fuel saturation. Faulty MAP sensor-ECM seeing higher than normal manifold pressure (low vacuum) system can go rich Intermittent TPS output will cause system to operate rich due to a false indication of engine acceleration O2 sensor contamination caused by silicone in certain fuels. Or improper use of RTV sealant could cause a false high signal (or low oxygen content sensed)is interpreted by the ECM as a rich mixture causing code 45 to be set. EGR problem- EGR sticking open at idle, but this is usually accompanied by a rough idle or stalling Your going to need a scan tool such as a Snap On MT-2500 or equivalent.The first thing i would do is to make sure the O2 sensor is capable of seeing rich and lean. Your also going to need the flow chart for the code which will walk you thru the diagnostic procedure. Hope this helps.. Jason
Thanks Jason, It does run rich at idle, and acts like it wants to stall. After you increase speed it comes out of it and surges and then runs smooth again. Does this give any more clues? Or would the procedure you mentioned be the same? I am currently in Chicago and do not have access to equipment or know any trust worthy shops. Patrick
Unfortunatly, without being in front of it, its difficult. In your situation, a quick scan of vacuum lines and connectors under the hood may help out. I dont think it will leave you stranded though. Jason
Your welcome,Pat.Thanks for the compliments on my car. The way your engine is running sounds like the O2 sensor-it would be a good idea if you have a scan tool check it out as Jason suggested.
O2 Pat, Like Jason mentioned many things can fool the computer, like a plugged cat will cause multiple codes EGR, O2's etc, I've seen shops replace EGR valves in the 4.3 that were sticky, with new ones and the problem was not the valve. It was carbon from the system its self,and they couldn't figure out why it kept setting EGR codes o No: electronic EGR valves are not cheap :eek2:First of clear the codes. Drive it untill it comes back then re check codes,some times the code won't come back.But if it does I think replacing the o2 sensor is a safe bet but check the wires going to the o2 for being damaged .I would think if the injectors were dumping fuel due to ECM,TPS or MAP problems it would be screwing up both o2s or setting other codes MAYBE o No: If you can't get a scan test by a tech,see if it resets the code and try a new one BUT make sure you install a AC Delco O2 the after market ones don't always work correct or at all right out of the box.Chris
service code lakota, a faulty fuel pressure regulator can also cause a rich running and stalling condition. two things to check on it. check fuel pump pressure with a fuel pump gauge. next carefully pull the vacuum hose attached to the fuel pump regulator. if fuel drips out of the vacuum hose it means the diaphram is busted on the regulator and it will have to be replaced. both the regulator and the schraeder valve for the fuel pump test are located on the fuel rail. of course be extremely careful and have a fire extinguisher handy when working on fuel related problems. good luck
I would bet you have a fuel leak inside the intake manifold. It is probably the fuel pressure regulator leaking. This fuel system is prone to failure. The plastic fuel pipes also split and leak fuel. Fuel pumps also fail, but will not cause you problem. 1994 seems to be the worst. The regulators only come with the fuel injector assembly. Big $$. Even if the pipes are not leaking I would recommend replacing them while you are in there. Also replace the fuel filter every 30,000 miles. The EGR problem is also common, but will cause a code 32 and poor idle. Carbon getting in the EGR can be a problem, especially after having fuel leak in the intake. If you drive it hard on a regular basis carbon should be less of a issue. This is a fairly easy repair, but you will need torgue bits. The bolt holding the pipe to the back of the engine is a SOB. The kit comes with a new bolt, but do not destroy the old one trying to get it out. HTH John
Pat,as you know,cars are difficult to fix-especially if you can't see them and everyone's picking straws and guessing. Of course the situation gets much more easier to diagnose when the vehicle is up in front of you and staring you in the face. As you can see,just one code can be triggered from a multitude of problems. That is what makes today's cars so difficult to diagnose. To really find and solve the problem,you need a plethora of tools and knowledge and those are two major things that the average car owner doesn't have. I really hope you find your problem, Pat. Good Luck!
Thanks everyone for the help. I got the truck over to Kevins house (10inchbuick). He is a great person and had the scanning tools and knowledge to address the problem. Minor really he surmised carbon built up on the ERG. He cleaned it up and put a new screened gasket on and the reading where good there after. Patrick
