‘87 454 R20 eye watering exhaust w/ windows down

[Ricko1966]

If your tailpipe exit straight back,the turbulence of air over and under the car push the exhaust fumes in through the open back window. Reroute the tailpipes to side,exit behind the rear tires just wider than the rear wheel track. The exhaust fumes get caught in the air stream to the side of the vehicle.

 

[Grit dog]

Just confirming what has been said. Old CJ5 soft top. I ran the (single) pipe straight out the back. No problem with top on. Would choke you out of the vehicle the faster you went with the back window and doors off.
Stuffed a 45deg bend on the end of the pipe, down and out to the side. Got rid of the majority of the fumes.

 

[Redfish]

So it looks like there might be an overlay on my dash. Is the check engine light behind it? Because I don’t see any cel in the gauge lights.

The Check Engine Light is actually a Service Engine Soon Light. It is in the bottom right side of the Speedometer. My camera sucks so you cannot read it but it is the orange light under the odometer.

You must be registered for see images attach

If your '87 still has the TBI system your problem is simple and re-routing the exhaust exit will not fix the problem.

The O2 sensor is giving your ECU bad information because you now have "true duals". If you have defeated the smog system that only adds to the issue. Your truck is running too rich. This seems to be worse at idle speeds, at least it was with mine. Your computer was designed to run with a choked up single exhaust, catalytic convertor and air pumping into the manifolds. If any part of that has changed the system is not going to function properly.

I fixed this problem by contacting Harris TBI in Virginia and getting a Stage 1 chip. Before I did this my exhaust gas would burn my eyes and my throat any time I was idling. Fuel mileage seemed to be okay but at idle it was awfully rich. After installing the chip a lot of things improved with how the truck runs. This is a simple and relatively cheap fix. I can answer any questions you have about getting to the ECU and replacing the chip. Brian Harris can tell you what you need to do to make it run better.

 

[Rickf]

Just curious, have you pulled and looked at the spark plugs?

 

[beady]

The Check Engine Light is actually a Service Engine Soon Light. It is in the bottom right side of the Speedometer. My camera sucks so you cannot read it but it is the orange light under the odometer.

You must be registered for see images attach

If your '87 still has the TBI system your problem is simple and re-routing the exhaust exit will not fix the problem.

The O2 sensor is giving your ECU bad information because you now have "true duals". If you have defeated the smog system that only adds to the issue. Your truck is running too rich. This seems to be worse at idle speeds, at least it was with mine. Your computer was designed to run with a choked up single exhaust, catalytic convertor and air pumping into the manifolds. If any part of that has changed the system is not going to function properly.

I fixed this problem by contacting Harris TBI in Virginia and getting a Stage 1 chip. Before I did this my exhaust gas would burn my eyes and my throat any time I was idling. Fuel mileage seemed to be okay but at idle it was awfully rich. After installing the chip a lot of things improved with how the truck runs. This is a simple and relatively cheap fix. I can answer any questions you have about getting to the ECU and replacing the chip. Brian Harris can tell you what you need to do to make it run better.

Thanks, I actually bought a 3-wire o2 sensor for my OBS that had true duals also, but the truck got hit before I installed it. Still have it, should work on this truck. I’ll email him.

 

[beady]

just pulled them today actually. Most looked pretty good. A couple were nasty and oily though. They did NOT all look black with soot/running rich though.

But…. I cross threaded #8 with the new plug : (. Going to post a new thread asking what my options are.

 

[Ricko1966]

just pulled them today actually. Most looked pretty good. A couple were nasty and oily though. They did NOT all look black with soot/running rich though.

But…. I cross threaded #8 with the new plug : (. Going to post a new thread asking what my options are.

Depends on how bad you buggered the threads,they make a thread chaser for plug holes,grease it,screw it in ,unscrew it. Easy peazy. As for the exhaust fumes,rerouting the tail pipes will definitely help. It's physics and science. Air going over and under the car creates a low pressure area right behind the car that pulls up the exhaust fumes,it's even worse if the side windows are down,air rushing by the sides of the open windows creates a vacuum. The air pulled out the side windows sucks the exhaust fumes in through the back window. It works like an old water bed syphon pump. It used to be,(maybe still is) illegal to run duals straight out the back on a station wagon with a window that opens, or a pickup with a camper. Those laws may have relaxed after the advent of catalytic converters,which remove,I think,90% of the carbon monoxide,we don't have the same problems with CO poisoning anymore.