diff --git a/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/gpuKernelEvaluator.cu b/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/gpuKernelEvaluator.cu
index 83712c7..64876fe 100644
--- a/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/gpuKernelEvaluator.cu
+++ b/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/gpuKernelEvaluator.cu
@@ -63,9 +63,9 @@ GpuKernelEvaluator::computeYNew(
 std::tuple<std::vector<gScalar>, std::vector<gScalar>, gScalar>
 GpuKernelEvaluator::computeRR(gScalar deltaT,
                               gScalar deltaTChemMax,
-                              const std::vector<gScalar> rho,
-                              const std::vector<gScalar> deltaTChem,
-                              const std::vector<gScalar> Y) {
+                              const std::vector<gScalar>& rho,
+                              const std::vector<gScalar>& deltaTChem,
+                              const std::vector<gScalar>& Y) {
 
     const gLabel nCells = rho.size();
 
diff --git a/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/thermosAndReactions.H b/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/thermosAndReactions.H
index f9c4881..e5c8465 100644
--- a/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/thermosAndReactions.H
+++ b/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/thermosAndReactions.H
@@ -11,7 +11,7 @@ struct thermosAndReactions {
 
     thermosAndReactions() = default;
 
-    thermosAndReactions(const std::vector<gpuThermo>    thermos,
+    thermosAndReactions(const std::vector<gpuThermo>&    thermos,
                         const std::vector<gpuReaction>& reactions);
 
     ~thermosAndReactions();
diff --git a/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/thermosAndReactions.cu b/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/thermosAndReactions.cu
index b6b81bb..ebfadae 100644
--- a/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/thermosAndReactions.cu
+++ b/gpu_chemistry/src/gpuKernelEvaluator/gpuKernelEvaluator/thermosAndReactions.cu
@@ -16,7 +16,7 @@ static inline T* allocateAndTransfer(const std::vector<T>& t) {
 }
 
 thermosAndReactions::thermosAndReactions(
-    const std::vector<gpuThermo>    thermos,
+    const std::vector<gpuThermo>&    thermos,
     const std::vector<gpuReaction>& reactions)
     : nThermos_(gLabel(thermos.size()))
     , nReactions_(gLabel(reactions.size()))
diff --git a/gpu_chemistry/unittest/gpuTestKernels/gpu_test_kernels.cu b/gpu_chemistry/unittest/gpuTestKernels/gpu_test_kernels.cu
index e432971..7e9fd12 100644
--- a/gpu_chemistry/unittest/gpuTestKernels/gpu_test_kernels.cu
+++ b/gpu_chemistry/unittest/gpuTestKernels/gpu_test_kernels.cu
@@ -658,7 +658,7 @@ bool test_for_each_index(){
 
 
 
-/*
+
 bool test_evaluator(gLabel nCells){
 
     using namespace FoamGpu;
@@ -704,26 +704,26 @@ bool test_evaluator(gLabel nCells){
     );
 
     auto newY = std::get<0>(tuple);
-    auto newDeltaTs = std::get<0>(tuple);
+    auto newDeltaTs = std::get<1>(tuple);
 
 
+    for (gLabel i = 0; i < nEqns; ++i){
+        std::cout << newY[i] << std::endl;
+    }
 
+    /*
     auto s2 = make_mdspan(newY, extents<2>{nCells, nEqns});
 
     for (gLabel i = 0; i < nEqns; ++i){
             std::cout << s2(0, i) << std::endl;
     }
-
+    */
 
     return newY[0] != 0;
 
 
-
-    //return true;
-
-
 }
-*/
+
 
 
 }
diff --git a/gpu_chemistry/unittest/tests/Test-gpuChemistry.C b/gpu_chemistry/unittest/tests/Test-gpuChemistry.C
index 352ec57..bebf240 100644
--- a/gpu_chemistry/unittest/tests/Test-gpuChemistry.C
+++ b/gpu_chemistry/unittest/tests/Test-gpuChemistry.C
@@ -845,11 +845,12 @@ TEST_CASE("for_each_index (on GPU)", "[GPU]"){
     CHECK(GpuTestKernels::test_for_each_index() == true);
 
 }
+
 /*
-TEST_CASE("Test gpuKernelEvaluator"){
+TEST_CASE("Test gpuKernelEvaluator (on GPU)", "[GPU]"){
 
-    CHECK(TestData::test_evaluator(1) == true);
-    CHECK(TestData::test_evaluator(2) == true);
+    CHECK(GpuTestKernels::test_evaluator(1) == true);
+    CHECK(GpuTestKernels::test_evaluator(2) == true);
 
 }
-*/
\ No newline at end of file
+*/