Forum Replies Created
-
Replies
-
As the catalytic converter goes bad, the p0420 code often sets on long trips. I don’t think the AC is related to this issue, except the long trip may have revealed an existing problem. Test the o2 sensor before replacing it, because there are codes for o2 sensor failure and p0420 isn’t the primary code for that.
You can use a recharge kit from any auto parts store to check the pressure in the AC system, and you can also listen for the AC compressor clutch engaging to diagnose the air conditioning problem.Can you unbolt the catalytic convertor from the exhaust manifold, just below the egr pipe connection? That might allow you to access the pipe. On the Altima I had in Texas, that was all one piece, with a support bracket bolted to the block at the bottom of the manifold/ downpipe assembly. Looks like you can go after 6 bolts connecting the pre cat to the exhaust manifold and possibly a support bolt and drop the pre cat out the bottom of the engine bay. It’s also got 3 nuts connecting it to a flexible exhaust line under the engine.
You got that exactly right! You need to connect the two wires that would plug into the switch to each other. Paper clip, jumper wire, etc which will allow you to test the concept. Then if it works, you can use a splice kit, or a short piece of wire and two terminal connectors to either plug into the plug, or orbjump the wires leaving the plug attached. That way if you decide to replace the module later the plug is still there.
How is the oil pan gasket? It certainly looks like the oil draining down the sides is either the valve cover gasket, the head gasket or the oil pan. But it’s not a bad idea to do the cam and crank seals along with the timing belt.
If it is the AC compressor, it should also drop the RPM on max AC. Many older cars used a system to retard the ignition timing to increase the rpms to keep the engine from dying. Do your rpms increase when you turn the AC on? Does the car idle a little slower than it should normally? Probably around 750 normally and 900 rpm with the AC on?
Does it sound like the engine is running faster than a normal idle? Do the problems go away while driving? Faster might point you toward diagnostic checks of the idle air control valve, while slower with a lot of shaking might send you toward ignition or fuel problems causing a misfire and possibly a check engine light.
Do you have an adjustment point under the hood? https://youtu.be/2VonSg0HUj4
Some sc2’s might. I think if you can’t get into reverse, the cable might have too much slack in it.Wikipedia shows the 2 nd gen cavalier ending in 1994 and a new body style from ’95-2004, with different engine designations in the vin# except for the 2.2 sohc. So the head is probably different dual cams instead of single, and the ecu probably went from obd I to obd II so it will probably have more, or slightly different sensors. Still the concept seems possible with a lot of electrical work and modification.
Did the car have any lockout feature to keep you from shifting into reverse instead of 4th gear? Any other gears that don’t engage perfectly?
Steel line with double fare unions is how I would go. You can replace partial sections, but the double flare and threaded unions are recommended for safety, both yours and ours!
Look for manufacturer specific apps. Fordsys has worked great on Ford’s and elmscan Toyota works good on Toyotas, providing ABS codes as well as engine codes.
Torque is the best app for live data, but only gives engine codes. And it costs $5 us. Still, it can graph 02 sensors and fuel trims simultaneously which other apps often struggle to do.A vacuum gauge can show intake vacuum decreasing when the valve is open so it might show unusually low vacuum at idle if the egr valve is still open. That’s about all the vacuum gauge can do. With a working egr, the valve moves when you rev the engine and then immediately closes again if there is no load such as during a test with the vehicle in park. Just remember the idle problem only happens if the egr is open at idle so if your new valve is working right, the problem should have been solved. Or maybe the valve is getting foreign objects from the upstream side or egr pipe and exhaust manifold that prevent it from closing all the way. Don’t worry about anything past the valve in the intake manifold to solve the idle problem. It’s the valve and the pipe before it, and the valve probably needs to be cleaned again.
If the egr is leaning out the mixture too much during acceleration, cleaning the passages will only increase the pressure and may make the problem worse. I’d clean them if they are dirty, but then look for a back pressure problem at the catalytic convertor. Maybe try running it with the pipe at the bottom of the exhaust manifold listened to take the rear convertor out of the system. A back pressure gauge would be nice here but loostening bolts is a cheaper test.
I never got my egr pipe off the exhaust manifold. The nut rounded off first. Maybe I should have used a torch. Anyway, I hope you have better luck with it. There are a lot of videos of the Maxima that tell you to clean a 4″ long pipe, but the Altima pipe is more like 2 ‘ long and of course the hottest end should have the most carbon buildup so I was quite disappointed when I couldn’t get mine off.
Good luck.You have removed the egr pipe with the valve. It connects to the exhaust manifold and loops around the engine under the distributor. The cast in passage for the egr appears to exactly where you indicated on your picture of the intake manifold. If I remember from my ’98 Altima the plugs have a hex head, but I never needed to remove them. Maybe try a large hex bit for a 3/8 drive ratchet and pray the corroded aluminum plugs don’t strip or round off.