94 Ranger 4.0 emission issues

[futurefd]

Purchased a 94 ranger, it failed emissions, the cat was hollow, and o2 sensors shot

replaced BOTH with new then during the retest it failed with double bad numbers.... any suggestions? I can get a waver and will but next year....

[flimmy]

If you have the recipts for the parts and its over $150 you can get a waiver. It will have to fail 2 times to get the waiver.

[tanz45]

Code numbers?

[flimmy]

you have to put a certin # of miles on the truck before getting it retested or it will fail even if you fixed the problems. I'm not sure how many but its something like 100. Maybe someone else can help with that

[joe_and_jeep]

you have to put a certin # of miles on the truck before getting it retested or it will fail even if you fixed the problems. I'm not sure how many but its something like 100. Maybe someone else can help with that

Its a 94, so its a tail pipe test. The 96 and newer OBDII have to go thru the drive cycle to reset the monitors. If your running double numbers then you got problems, what was it? Idle or 2500RPM? And you can get a waiver next year, but it goes from $150 minimum repair to $250.

[flimmy]

I just got a waver for my tacoma and it was $150 in parts and that can include oil and filter. It had to fail 1st then buy parts and install them, then fail again. Then you can get the waiver. Thats the way it worked for me in Oct.

[DixieJeeper]

You likely have a fuel trim issue- just becasue you had O2 or TWC efficency codes doesn't mean the O2's were bad. It means that the O2's were seeing readings that didn't correlate to what it should have been seeing.

Most often O2 sensors are incorrectly replaced becasue they have a "code", (certainly some are defective). However, when you replace an O2 and the "numbers" (I am assuming you mean the lamda/voltage readings) get worse it is only due to the fact the sensor is new and reading the exhast better than the old sensor(s)--now only reading the root casue of the issue better0 which is a fuel trim issue.

Fuel trim is the PCM riching and leaning out the the fuel injectors in response to the O2 readings. You can get o2 codes due to faults with fuel trim which would be, vaccum leaks, fuel injectors sticking, air inlet leaks, MAF and MAP sensor faults.

Since you replaced O2 sensors with no change only worse "numbers" you likely have one of the above.

Waiver's are parts and labor total- so if you do the work yourself you have to spend 150 in parts and it has to be tested twice.

[joe_and_jeep]

The numbers he's taking about is Hydrocarbon and Carbon Monoxide. In PA (some counties) use an exhaust analyzer to test 1985-1995 vehicles for emissions. His is a 1994 so that would of been the test. It tests at idle and 2500rpm. Its 1996 and newer that has the OBDII.

The waiver for the first year is $150 of parts/labor to repair the problem. Only parts related to the problem can be used. If it fails the second year the waiver amount jumps to $250.

[DixieJeeper]

I wasn't sure if he was looking at the test results on the VIR or if he was trying to diagnosis via a DVOM or scantool. The post wasn't clear...

Either way if he is still running rich he has some sort of fuel trim issue.

If he is failing for NOx its either an EGR or TWC issue.

We need a little more information if you want to try and fix the issue.. Just remember to qualify for a waiver when you are doing the repairs to obtain the waiver you can't use any labor as a DIY meaning you have to throw more parts at it to qualify for the dollar amount.

If you have any other questions there are alot of us that are PA SI/IM techs on here and some including myself have the Repair Technician cert to write waivers.

[flimmy]

The waiver for the first year is $150 of parts/labor to repair the problem. Only parts related to the problem can be used. If it fails the second year the waiver amount jumps to $250.

I have a question about waivers. I bought my tacoma from my stepson. I took it and got the waiver before we transfered the title. If I need another one next yr will it be $150 or $250 ? The truck is now in my name not his.

[DixieJeeper]

Its by registered owner so it will be 150 parts and labor- or 150 parts if you do it yourself and 2 tests.

[flimmy]

Thanks

[joe_and_jeep]

I have a question about waivers. I bought my tacoma from my stepson. I took it and got the waiver before we transfered the title. If I need another one next yr will it be $150 or $250 ? The truck is now in my name not his.

What year is the Tacoma and why didn't it pass? Its odd that a Toyota wouldn't pass.

[flimmy]

What year is the Tacoma and why didn't it pass? Its odd that a Toyota wouldn't pass.

Its a 2000 with the 2.7. Check eng light is on and it has been a pita to track down the problem. I just unplugged the upstream o2 and its running fine and getting about 20 mpg depending how I drive. I realy think its the tps but have yet to get a new one. I might just wait till next oct. and try that and if it doesnt fix it I'll have that and do an oil change , filter and air filter and have my $150 and get another waiver. I'll fix it but I just dont have the time right now.